Yuan-ti eggs - what are your thoughts?

[hymer]

I didn't realize until this edition (and not until Volo pointed it out) that yuan-ti would be more likely to lay eggs than give live birth. It makes sense. But what would adventurers see, coming across a clutch of these eggs?
As for size, I assume at most the size of the head of a newborn baby for medium sized mothers. If they're laying a clutch of eggs, they'd likely be much smaller, on the thinking that they all come out pretty much at the same time. Perhaps a total mass pretty much equal to a newborn human. I assume that's how snakes do it, and I'm trying to expunge hens from my thinking here. Effectively going into labour five or more times in a week would be pretty dangerous for humans, I expect, to lay a clutch of the biggest eggs they could.
As for shell, I'd assume a fairly rubbery thing? I've never touched a snake egg, but the ones I've seen were pretty much white, or with some brown on them, presumably to be hidden underground where their colour won't matter. If you're going to lay eggs in a nest aboveground, you may want to have brown eggs instead to avoid attracting attention.

So what do you guys think about yuan-ti eggs?

[Regitnui]

I've not actually thought of that until now.

Perhaps the lower castes give live birth and find it disgusting, degrading and horrifying. Hence why they'd hand off newborns to the broodguard with the other eggs as soon as possible. The irony would be that live-birth yuan-ti are eventually stronger than hatched. Also, there'd be no way for a given pureblood or malison to know if she'd lay or birth before she actually has to.

The broodguard (if they're equipped for it) probably don't have enough mind to care. The yuan-ti might even kill broodguard who become sluggish during their pregnancy/brooding, so who knows?

I personally am not a herpetologist, so I know next to nothing about snake eggs. I think yuan-ti eggs might be similar in texture, with one at a time, but no specific mating season or designated fertile time, like humans. Perhaps there's a culturally designated day/week in a particular yuan-ti community before a short period of increased raids. You need new broodguards for new eggs, after all.

Finally, I think that the burden for reproduction would be placed on the lower castes. Not that abominations and anathema can't mate or wouldn't want to, but they have more important tasks and there's less of them in general. Also, a higher caste yuan-ti can be made from a lower one, so as long as there are many purebloods, there's no reason that malison and abomination yuan-ti have to raise young at all when they can pick from suitable adult candidates of the next caste down.

Eww... And I hope that's the last I ever have to think of snake people doing the dirty.

[hymer]

@ Regitnui: Well, I want to thank you for your thoughts all the more for how squicky you found it. :smallsmile:

[Scathain]

Serpent Kingdoms and Ecology of the Yuan-ti (dragon magazine) from 3.5e gave a lot of insight into egg hatching habits of Yuan-ti. I'm AFB rn, but Anathemas/Abominations would pretty much decide when official egg laying periods are, perhaps coinciding with rites to Sseth/Mershaulk. Some YT leaders even ritualistically eat eggs as offerings, but only they are allowed to tamper with them, for anyone else (especially an adventurer) it would spell certain death. I can already see a Jurassic 3 rip off where an NPC steals yuan-ti eggs and the party is chased relentlessly by angry parents.

This religious zeal around proper egg hatching times led to one of my favorite characters of all time: a yuan-ti pure blood wizard who was born outside of the traditional birthing times, and exiled for it. There's a lot you can do with YT eggs to make some fun encounters.

[MinotaurWarrior]

I'd make each egg larger than a typical newborn baby. Maybe 12lbs. I'd expect hatched Yuan-ti to be more functional than newborn humans, at least capable of moving on their own, identifying food, and ingesting it. Not a draganoid "combat encounters with sapient children" level of capability, but just enough that the adult Yuan-ti don't need to play mamal and do everything for their newborns. Maybe once a day they drop a maimed animal into the children's pit, to be eaten alive by the strongest among them, who manage to shoulder their way to the front of the feeding frenzy.

[Temperjoke]

Well, I don't have Volo's so I can't reference that, but the MM says that they were originally humans that were turned snake-like, which is why Pure-bloods are the lowest castes typically because they most resemble the original human stock. If that's the case, they might actually give live birth like regular humans. Even if they don't, there are some snakes that give birth to live babies instead of laying eggs.

[Joe the Rat]

Food for thought: Mmmm... Serpent eggs...

Broadly speaking, reptile eggs are oblong and leathery - slightly soft. That can be squeezed a little. Early gestation has very little development to be upset by the egg-laying process.
Eggs can get larger after being laid. Most of the mass is food/building supplies; air can be absorbed through the shell. Plus, y'know, magic.
Some reptiles do live birth. Some sharks do live birth. Some sharks produce eggs, then carry them until they hatch. Weird magical hybrids give you lots of reproductive options.
Since all (?) Yuan-ti can take on a human shape, they might all be born (mostly) human-looking, then mature into their transformations.

[Regitnui]

Serpent Kingdoms and Ecology of the Yuan-ti (dragon magazine) from 3.5e

Which issue was that? I've got a compendium of them, so it'll be interesting reading.

[hymer]

@ Scathain: Good thoughts, thanks!

@ MinotaurWarrior: How would the mechanics of that work? I mean, the reason human babies are born when they are is that it's usually the latest you can expect to get their heads out. Would the eggs be like large sacks that could be squeezed safely?

@ Temperjoke: Well, Volo says that most yuan-ti lay eggs, and some give live birth, and I think I'll stick with that. As Scathain and Joe point out, there is a lot of fun stuff you can do with eggs that would feel sick and weird with live young.

@ Joe the Rat: Thanks for that info. Sounds like you shouldn't squeeze them too much, but they won't up and crack like a hen's egg.

@ Regitnui: Issue 151 IIRC.

[MinotaurWarrior]

@ MinotaurWarrior: How would the mechanics of that work? I mean, the reason human babies are born when they are is that it's usually the latest you can expect to get their heads out. Would the eggs be like large sacks that could be squeezed safely?

1) Magic
2) The advantages of not being bipedal. Iirc, the hard constraint on human gestation is that the range of newborn cranial diameters absolutely cannot be in risk of exceeding a certain measure of the pelvis, and the pelvis in turn needs to be shaped a certain way or we can't walk. I don't even think abominations or type 3 malisions have hip bones.

But more one than two. I wouldn't even let the biology stop me from having the total mass of eggs exceed the mass of the mothers, if the scene demanded a lot of eggs and not so many moms. Everything about them is explicitly unnatural, so why not.

[Regitnui]

Everything about them is explicitly unnatural, so why not.

That's actually wrong. Explicitly unnatural beings are aberrations, whereas yuan-ti are humanoids/monstrosities. Their biology isn't magical, but their origins are. The owlbear and ankheg are also monstrosities by MM standards, and they're entirely natural barring one or two oddities. Even an Anathema is a monstrosity, bound by the basic needs of eating, breathing, drinking and assumably also the physics of popping eggs out of its serpentine cloaca.

That's assuming, of course, that anathema reproduce at all instead of just being created from abominations. In any case, the point still stands. A yuan-ti can't ignore physics when birthing; they're not illithids or neogi.

[MinotaurWarrior]

That's actually wrong. Explicitly unnatural beings are aberrations, whereas yuan-ti are humanoids/monstrosities. Their biology isn't magical, but their origins are. The owlbear and ankheg are also monstrosities by MM standards, and they're entirely natural barring one or two oddities. Even an Anathema is a monstrosity, bound by the basic needs of eating, breathing, drinking and assumably also the physics of popping eggs out of its serpentine cloaca.

That's assuming, of course, that anathema reproduce at all instead of just being created from abominations. In any case, the point still stands. A yuan-ti can't ignore physics when birthing; they're not illithids or neogi.

Sorry, unnatural was perhaps the wrong word. The entry on monstrosities uses the somewhat awkward "not natural". Maybe "sorcerous" would have been better for Yuan-Ti:

"Through foul sorcery, the yuan-ti bred with snakes, utterly sacrificing their humanity to become like the serpent gods in form, as well as in thought and emotion."

Regardless, the abominations and Malisions can shapeshift, and all Yuan-ti have innate spellcasting powers. I'd feel comfortable using that to handwave minor biological concerns like cloacal elasticity.

[Regitnui]

Sorry, unnatural was perhaps the wrong word. The entry on monstrosities uses the somewhat awkward "not natural". Maybe "sorcerous" would have been better for Yuan-Ti:

"Through foul sorcery, the yuan-ti bred with snakes, utterly sacrificing their humanity to become like the serpent gods in form, as well as in thought and emotion."

Regardless, the abominations and Malisions can shapeshift, and all Yuan-ti have innate spellcasting powers. I'd feel comfortable using that to handwave minor biological concerns like cloacal elasticity.

The owlbear also has "sorcerous" origins. They're breeding perfectly well. But that's off topic.

It's entirely possible as is, given skeletal structures of humanoid and serpents, that the yuan-ti breed either way, no magic required. Let's not forget they have an entire caste designed to care for young. I'd go with the natural method for their forms; purebloods and humanoid malisons give live birth and serpent-bodied (ophidian?) malisons and above lay eggs. The pureblood caste is designed to infiltrate human societies, after all, and it'd ruin years of infiltration if the new queen pops out an egg in front of the royal midwives.

Eww.

Anyway, the Ecology of the Yuan-ti article offers another angle; hisstachi (sp?). Essentially the conceptual forerunner of the broodguard, a hiss-tacky is supposedly a breeding factory for purebloods, since two yuan-ti result in the next caste up. This means that the yuan-ti need to raid for human(oid)s before breeding, or they run the risk of losing their disguise. I can see why the hiss-taco was dropped in favour of the broodguard, since they're formed in roughly the same way and don't imply the whole "Mars Needs Women (http://tvtropes.org/pmwiki/pmwiki.php/Main/MarsNeedsWomen)" narrative. But, for us brave few who dare venture into realms untrodden since the BoEF, the concept has some points that can be taken forward. Purebloods (ironically) are half-breeds, with malisons representing either deviations or progressions into the final form of the abomination.

Note here that unlike the drow, who idolize the arachnid form, the yuan-ti have taken the step of becoming like their ideal (the equivalent is drow intentionally becoming driders). The yuan-ti, even in their most monstrous or 'highest' form, don't become entirely snakelike. The abomination is assumedly the end result of yuan-ti modification, with the anathema being a corruption/upgrade of that.

If we take the progression of generations as still in place, minus the his-tracker, the yuan-ti likely are mostly abominations in any given population. Going by that, it's likely that a band of intrepid and unlucky adventurers stumbling into a yuan-ti's nursery would find leathery eggs and hatchlings, not babies and toddlers. The rare live-birth would likely be killed early on by their more-developed hatched counterparts. This is excluding the broodguards and whatever yuan-ti parents find themselves motivated to crush the ignorant humanoids for endangering their children or the future of the colony. (I know that they emphasize the emotionlessness of snakes, but if crocodiles can care for their young, a yuan-ti would have some maternal or paternal instinct towards juveniles of their species.)

[MinotaurWarrior]

The owlbear also has "sorcerous" origins. They're breeding perfectly well. But that's off topic.

No they don't. There's a rumor that a wizard did it with crossbreeding (wizardry =/= sorcery, if you're going to play at pedantry), and a elven ancestral memory of their origins in the Feywild. Also, if we're worrying about pelvic / cranial proportions for reproduction, owlbears actually do produce a problem, since their owl part is the oversized inflexible skull, and the bear part includes the pelvic structure. The fur makes it somewhat unclear, but the widest part of their skull appears to be about as wide as their haunches, which would mean that either owlbears give birth to young that are even less developed than that of a normal bear, or that who the hell cares let's hand wave it these are DnD Monstrosities we're talking about.


Anyway, the Ecology of the Yuan-ti article offers another angle; hisstachi (sp?). Essentially the conceptual forerunner of the broodguard, a hiss-tacky is supposedly a breeding factory for purebloods, since two yuan-ti result in the next caste up. This means that the yuan-ti need to raid for human(oid)s before breeding, or they run the risk of losing their disguise. I can see why the hiss-taco was dropped in favour of the broodguard, since they're formed in roughly the same way and don't imply the whole "Mars Needs Women (http://tvtropes.org/pmwiki/pmwiki.php/Main/MarsNeedsWomen)" narrative. But, for us brave few who dare venture into realms untrodden since the BoEF, the concept has some points that can be taken forward. Purebloods (ironically) are half-breeds, with malisons representing either deviations or progressions into the final form of the abomination.

The Mars Needs women angle is somewhat held down by the logical preference for kidnapping men (who can breed with many female Yuan-Ti) though that of course runs into the evil seductress archetype. Whatchya gonna do. Honestly, if your players are sensitive about these issues, you probably just shouldn't run an adventure about evil monsters kidnapping people to use as sex slaves.


Note here that unlike the drow, who idolize the arachnid form, the yuan-ti have taken the step of becoming like their ideal (the equivalent is drow intentionally becoming driders). The yuan-ti, even in their most monstrous or 'highest' form, don't become entirely snakelike. The abomination is assumedly the end result of yuan-ti modification, with the anathema being a corruption/upgrade of that.

Yeah, Sseth and Merrshaulk are supposed to be Yuan-Ti Abomination shaped, not snake shaped.


If we take the progression of generations as still in place, minus the his-tracker, the yuan-ti likely are mostly abominations in any given population. Going by that, it's likely that a band of intrepid and unlucky adventurers stumbling into a yuan-ti's nursery would find leathery eggs and hatchlings, not babies and toddlers. The rare live-birth would likely be killed early on by their more-developed hatched counterparts. This is excluding the broodguards and whatever yuan-ti parents find themselves motivated to crush the ignorant humanoids for endangering their children or the future of the colony. (I know that they emphasize the emotionlessness of snakes, but if crocodiles can care for their young, a yuan-ti would have some maternal or paternal instinct towards juveniles of their species.)

I'd also recommend you not have liveborn toddlers running about for the same reason as when fighting orcs or hobgoblins. That's just way too dark for most DnD groups. I'd also scrap your bit about the Yuan-Ti committing infanticide, though obviously YMMV

[Regitnui]

The Mars Needs women angle is somewhat held down by the logical preference for kidnapping men (who can breed with many female Yuan-Ti) though that of course runs into the evil seductress archetype. Whatchya gonna do. Honestly, if your players are sensitive about these issues, you probably just shouldn't run an adventure about evil monsters kidnapping people to use as sex slaves

*snip*

I'd also recommend you not have liveborn toddlers running about for the same reason as when fighting orcs or hobgoblins. That's just way too dark for most DnD groups. I'd also scrap your bit about the Yuan-Ti committing infanticide, though obviously YMMV

I'm operating group-agnostic, just trying to come up with internal consistency.

The whole his-'stache thing is one of those better left behind. Whether they steal ladies, men, both or neither, it raises Unfortunate Implications and would make most groups uncomfortable. Like you said.

The yuan-ti aren't committing infanticide any more than a eagle chick throwing its sibling out of the nest. We're talking extreme bullying rather than children murdering. Again, though, this is a reason for the lower castes having live young but the players not seeing any. Alternatively, a hatchling looks an awful lot like a toddler....

But that's our subject.

[Finback]

No they don't. There's a rumor that a wizard did it with crossbreeding (wizardry =/= sorcery, if you're going to play at pedantry), and a elven ancestral memory of their origins in the Feywild. Also, if we're worrying about pelvic / cranial proportions for reproduction, owlbears actually do produce a problem, since their owl part is the oversized inflexible skull, and the bear part includes the pelvic structure. The fur makes it somewhat unclear, but the widest part of their skull appears to be about as wide as their haunches, which would mean that either owlbears give birth to young that are even less developed than that of a normal bear, or that who the hell cares let's hand wave it these are DnD Monstrosities we're talking about.


The other question is - are they actually owl heads, or simply convergent to owl heads, like how thylacine skulls and canid skulls are similar generally, until you get to the fine details like the dentition count or the nasal turbinates.

[Regitnui]

The other question is - are they actually owl heads, or simply convergent to owl heads, like how thylacine skulls and canid skulls are similar generally, until you get to the fine details like the dentition count or the nasal turbinates.

Convergent Magic-Assisted Evolution?

[Zorku]

Also, if we're worrying about pelvic / cranial proportions for reproductionStrictly speaking, we don't have to worry about that. Quadrupeds can have a much wider pelvis than bipeds. Goofy holdover anatomy from early fish-frogs and whatnot.



Anyway, reading into snake birthing behavior, they lay quite a few (reticulated pythons, which top out at about 150lbs, lay 60-70 tennis ball sized eggs,) and tend to be just sticky enough to adhere to each other. Pythons pretty much lay them in a pyramid shape, which they coil around so that they can regulate the incubation temperature and humidity more carefully, and for some the eggs never even touch the ground. They have to regulate their eggs in this way for about three months.

Looking at some non-python articles, female snakes tend to try and fatten up in the spring, eating about twice as much as a male will, and they continue this trend through pregnancy. Smaller snakes means fewer eggs, but they're still likely to lay at least 10 at the low end, but more typically between 15-30, depending on species. Aside from pythons, most snakes don't care for their eggs after they lay them.


So, where the largest of Burmese pythons are 200lbs and about as big around as a telephone pole, you're going to a considerably larger snake-base for a Malison or Abomination with the general mermaid or centaur type transition in body plan below the waist. With the few data points I have I can extrapolate to clutches of nearly 100 eggs the size of tennis balls- if we're going purely off of snake biology. Human infants tend to have heads about twice as wide as that, so you can pretty reasonably choose any size in that range.

For anyone of the mindset that human infants have to have heads this big because of their brain, here's a slightly different take on the genetics behind that.

You generally think of natural selection choosing genes that are the best for the species altogether, but the whole sexual reproduction thing opens up a few avenues for selfishness. The easiest to understand is probably the difference between genders. In a female context you take a pretty big hit to fitness if your first child does so much damage that you die in childbirth, or are otherwise made infertile, so you'll want to generally slow down pregnancy and keep any baby below a certain size. In a male context there's no such risk, so as far as having a bigger baby will improve the health, and thus survival, of your offspring, you want that. There are a lot of quacks that try to oversell epigenetic factors, but this is one case where we know that epigenetics alters how a few genes work based on whether you got them from mom or dad. The same kind of conflict exists entirely within a female context, for much the same reason. During development it's in your best interest to be greedy and grow as big as you can, even if the same genetic course puts your health at risk when it's your turn to reproduce.

As you probably know, modern humans are kind of riding the edge there, such that pregnancy is fatal to both mother and child quite a lot more often than we're really comfortable with, albeit in a greatly reduced manner given modern medical techniques. The genetic context we're more interested in is some species a whole lot more like a chimp. The babies here are pretty much ideal in size for the best return of investment, and they're born mature enough to hang on to mom. Humans aren't born in that state, and they just about have to be held all of the time. Unlike snakes, human mothers can't just survive on fat until their young reach this level of maturity, which means they've got to hand the kid off to someone else. Usually dad, but sometimes grandma and grandpa. As heads get larger and babies are born more premature to avoid skeletal conflicts, we're looking at a much worse return on investment. There's nowhere else to invest though, so we're stuck in a bad situation, maybe exactly the kind of situation that takes violent chimp behaviors and turns them into the war type behavior we see in humans.



The truth is probably somewhere in between that idea and the one you're more familiar with, but the reason it was worth bringing up is that these snake heads don't necessarily have to emerge from an egg as big as a human infant's head if you want them to have comparable intellect. Natural selection is really bad at altering early developmental stages without radically altering the end result, but that sort of thing seems much more in line with dark rituals to your gods that turn you into a monstrosity- and the end result is still biologically sound (enough.)

I've got a couple other biology rants about why snake-people eggs ought to be roughly like this, but not enough time to type them up (and chances are you've barely got the time to read this much anyway.)

tldr; They should lay about 80 eggs, 3-4 inches wide. Pass them off to the brood guards quickly and make those jerks fast for several months to maintain these energetically expensive eggs. Well ok, maybe somebody else brings the broodguards take out/slop while they incubate the eggs.

Edit: Found a youtube video that leads me to believe that twins and triplets are rather common.
https://www.youtube.com/watch?v=1STOyZNNtPo
Not sure how broadly that happens in any given clutch (obviously this was video worthy for being extreme,) but you can pick up a lot of details about what snakeegg shells are like from the video.

[hymer]

@ Zorku: Thank you very much! That was a lot of useful info. :smallsmile:
Btw, I recently read an article (http://www.bbc.com/news/science-environment-38210837) about how caesarian section is slightly pushing the size of babies upwards (on average), which deals with the same question as the one you're talking about with the genetics - child's health vs. mother's health.

[Zorku]

@ Zorku: Thank you very much! That was a lot of useful info. :smallsmile:
Btw, I recently read an article (http://www.bbc.com/news/science-environment-38210837) about how caesarian section is slightly pushing the size of babies upwards (on average), which deals with the same question as the one you're talking about with the genetics - child's health vs. mother's health.
If that sort of reading is your cup of tea, you should look into gestational diabetes.

I also feel kind of derp for not naming the epigenetics diseases I spoilered for length. Prader-Willi and Angelman syndromes are the pair I learned about in college.

[Envyus]

The yuan-ti aren't committing infanticide any more than a eagle chick throwing its sibling out of the nest. We're talking extreme bullying rather than children murdering. Again, though, this is a reason for the lower castes having live young but the players not seeing any. Alternatively, a hatchling looks an awful lot like a toddler....

But that's our subject.

Yuan Ti Young actually feature in Rise of Tiamat. Were they are given the same statblock as a swarm of Poison Snakes. The Yuan ti actually try to knock the characters into the hatching pit containing them so they will be attacked. Also here is a small quote about them.


Yuan-ti produce copious young, which are consumed by their siblings so that only the strongest survive. A swarm of these young crawl through piles of eggs and crushed egg shells littering the floor,

So they do encourage the babies to eat each other. Along with the fact the Yuan ti do have rituals were they sacrifice eggs or young.

[Regitnui]

Yuan Ti Young actually feature in Rise of Tiamat. Were they are given the same statblock as a swarm of Poison Snakes. The Yuan ti actually try to knock the characters into the hatching pit containing them so they will be attacked. Also here is a small quote about them.



So they do encourage the babies to eat each other. Along with the fact the Yuan ti do have rituals were they sacrifice eggs or young.

I did not know this...

[Zorku]

Well, eggs are a fairly minor calorie investment in general, so if they're going to have anything remotely like a human population while laying this many eggs they'd probably need a type 3 survivorship curve (https://en.wikipedia.org/wiki/Survivorship_curve), though with the brood guard offering some minor care I could see it being a little more type 2. Since they're humanoid(-ish,) they're not going to feature as major prey for some other species, so we're pretty much forced into having them kill each other off.

I'm aware of a few birds that feature siblicide. They usually lay a small number of eggs, with a delay, so that the first to hatch can easily kill the last to hatch, but if something goes wrong with the first then the second is still there to prevent the season from being a total wash. The other example that's near to a lot of our hearts is the spotted hyena, where the females are masculine while the males are feminine. These seem to display a strange disparity where same gender twins are nearly nonexistent (though there was some dispute about that last I checked, so take this with a grain of salt.) It appears that a few factors come into play with that. Because most females are in a very debilitated state they have to birth somewhere that other hyenas can't get to their young, which consequently means that they won't intervene either. The young get to live in abandoned aardvark dens for the first few days, and this is an easy opportunity for siblicide. Being bigger is really valuable in the hyena hierarchy, so if you can monopolize mama's milk at this stage you very much want to do so. Furthermore, your status is most likely going to be closely tied to your mother's status, so a same gender sibling is going to be a serious rival if you both live to adulthood, and generally eat into your cut of the food and whatever other privileges the pack can allot to you. With male-female twins this doesn't come to a fatal end because the male is automatically submissive to the female, and just accepts whatever is left over after the girl has had her fill, so there's no worry about later rivalry.

The kind of snakes we're talking about aren't a close match for either of these examples, but when you bring in the human origin we can make a pretty tight narrative with this. With the birds you have a tight seasonal investment with parental care (even if it's more like mentally stunted nanny care here,) and with the hyenas you have a barrier between the genetic parents and a fairly intense social structure where it's only going to get harder to kill your rivals the longer you wait to do so.

I'm picturing something almost like a corporate ladder where in name the Yuan-ti are thought to be more capable and productive the higher they can climb, but everyone knows that after the first few rungs it's much more a game of getting dirt on your superiors while you sabotage your peers to try and strand them on lower rungs while you're shooting to the top. In a modern fantasy setting they'd probably be wearing (the top half) of business suits, complete with a snake themed tie. Maybe it's forked.

[Regitnui]

I'm picturing something almost like a corporate ladder where in name the Yuan-ti are thought to be more capable and productive the higher they can climb, but everyone knows that after the first few rungs it's much more a game of getting dirt on your superiors while you sabotage your peers to try and strand them on lower rungs while you're shooting to the top. In a modern fantasy setting they'd probably be wearing (the top half) of business suits, complete with a snake themed tie. Maybe it's forked.

Well, we know that there is a hierarchy in yuan-ti society; the purebloods defer to malisons who obey the abominations who are subjugated by anathema. The malisons also have an internal hierarchy, with the Volo's Guide variants of malison (humanoid with tail and humanoid with scales) explicitly called out as lower than the MM variants. It's not so far off to theorize that the infants are in a similar situation, where the baby purebloods get less than the various infant malisons who lose food and care to the juvenile abominations.

It may also be reasonable to assume that there are larger numbers of the lower caste; pureblood infants may outnumber malison younglings, and abominations are rarely seen. This might counteract the 'bullying' (survival curve?) theorized above.

The Broodguard may be as much regulators as carers; They're barely smart enough to receive and obey orders along the lines of 'more purebloods', which would twist the established pecking order in the egg pits on its head as the purebloods are favoured and protected by the broodguard until the order changes.

An alternative is that the separate castes have separate breeding pits; the adventurers in RoT are knocked into a low-ranking malison nest, for example, leaving the abomination cradles unmolested and the pureblood nurseries out of the invader's reach. Then the broodguards are more akin to worker bees in the hive, feeding the various castes as necessary to provide the colony with the 'right' balance of inhabitants.