Fun Monsters

[Voltage89]

For my campaign, we just played the first session and I am rethinking my one idea. There is an evil necromancer that is capturing people and feeding them to large abstract monsters and wishes to use them to take a city. The players just broke out of one of these prisons. There is also a potion that they are being told can help in the process, but it is actually for the evil necro. I want the players to beable to chose whether they want to go save people from the two prisons, or go slay these monsters for the potion. However, I don't know what monsters I want to be used in the potion. The players are only level 2 and I want the encounters to be interesting. Any ideas? They are in a forest/mountain area.

[Unoriginal]

For my campaign, we just played the first session and I am rethinking my one idea. There is an evil necromancer that is capturing people and feeding them to large abstract monsters and wishes to use them to take a city. The players just broke out of one of these prisons. There is also a potion that they are being told can help in the process, but it is actually for the evil necro. I want the players to beable to chose whether they want to go save people from the two prisons, or go slay these monsters for the potion. However, I don't know what monsters I want to be used in the potion. The players are only level 2 and I want the encounters to be interesting. Any ideas? They are in a forest/mountain area.

Gibbering Mouthers?

[Voltage89]

I'm using gibbering mouthers in the prisons, but I just need monsters for a potion. The players are going to go out and have to slay these monsters and collect there blood and such. I was thinking Griffin blood, but idk what else.

[JellyPooga]

If I've got this straight, you want suggestions for the blood (or other products) of creatures to go into some evil potion; stuff like unicorn horn, dragons breath and, as you mention, griffon blood, right?

If so, we need to establish how suspicious you want this to be. Asking for the blood of virgins and the still beating heart of a couatl might be a tip to the adventurers that they're working for the bad guy, you know? You can make a point of it, perhaps, by starting them off with going to get more innocent seeming things, like an elfs hair or naga's shed skin, and progress slowly up to a pixies wings, freshly picked and a nymphs tears under torture; lure them into the deed and slowly dawn the realisation on them, as their tasks become increasingly nefarious, that they are just pawns of a monster.

[Voltage89]

If I've got this straight, you want suggestions for the blood (or other products) of creatures to go into some evil potion; stuff like unicorn horn, dragons breath and, as you mention, griffon blood, right?

If so, we need to establish how suspicious you want this to be. Asking for the blood of virgins and the still beating heart of a couatl might be a tip to the adventurers that they're working for the bad guy, you know? You can make a point of it, perhaps, by starting them off with going to get more innocent seeming things, like an elfs hair or naga's shed skin, and progress slowly up to a pixies wings, freshly picked and a nymphs tears under torture; lure them into the deed and slowly dawn the realisation on them, as their tasks become increasingly nefarious, that they are just pawns of a monster.
Yep that's exactly what I'm looking for. The problem is that they are very low level so things like a unicorn would destroy them. That was kinda my goal though. Slowly move up into more destructive tasks.

[MxKit]

Cockatrice. The PCs might know about cockatrices, and they might agree because it sounds super easy as well as helping them, right? They're small, they're 1/2 CR, they have 11 AC and 27 HP, they're basically like chickens that can maybe petrify you, but how hard could they really be? Now, decide that the cockatrices in the area live in flocks. They find the tiny chicken monster they're supposed to hunt for parts and find that there are like a dozen of them right there and leaping at them.

Ettercaps. Sort of the same situation as above, only potentially way worse; you might even want to let them get in another level with another monster first. "A forest infested with ettercaps transforms into a gloomy place, choked with webs and infested with giant spiders, giant insects, and other sinister predators." Which means an infested forest could fit perfectly into your setting, but at CR 2, even a few of these things could be a problem, much less their insect posse.

Night Hag. Maybe they don't even need to kill her (she's CR 5 all by herself!). Maybe they just need her heartstone...

Jackals. They aren't bad at all, and neither is the jackalwere, which would be the actual star of this show. But maybe they're told they need a few parts from jackals, not even sounding like a big deal, jackals aren't even actually monsters... But maybe this pack of jackals is under the protection/jurisdiction of a jackalwere or two. For extra fun, this could even mean the players make an enemy of a lamia without even realizing it, if they kill her jackalwere servants (lamia are CR 4; you could bring one in shortly if you wanted!).

Manticores. Even two manticores would be a deadly challenge, while one would probably be fairly easy due to action economy, so be careful. Still, if they needed four manticore eyes... Or even just a single manticore tooth but found a pair, or even one and a child (just stat it a bit downward)... Or maybe just the one, but it serves orcs or hobgoblins and the players have to get through those somehow (battle or stealth) to get to it.

Mimics. Maybe they need to actually figure out how to find a goddamn mimic and get one of its teeth... or some of its drool. Finding it could be the hardest part, though going through a dungeon with the mimic actually being the treasure could be kinda funny.

Oozes. Similar to the mimic above. If you need to break off and put part of an ooze into a container, that could be kind of funny and very hard. A black pudding would be the most challenge, but a gelatinous cube is of course the ooze and might be fun for your players to figure out how to deal with.

Trolls. A troll is CR 5, and even a single one could be an issue for them, even with the action economy. Especially if you give it loathesome limbs, and if your players don't know about its weakness to fire. But still, it'll be memorable!

Flail Snails. I just really like flail snails, okay. If you have the players have to track down a couple of them, they can be a really unique fight. Plus, if they just need one shell so that the potion can be made, but run into a pair of them, a)a bit of a harder fight and b)they can use the second flail snail's shell to have three sorta-magical shields made (that can even be turned into spellguard shields later maybe), or a single robe of scintillating colors, if you want them to be able to get any of those things.

"A worm from a zombie." AKA maybe your players just think they're going into a little area that has an undead problem, and maybe it really is mostly regular zombies... except with a single spawn of Kyuss, from which they have to get one of the tiny green parasitic worms. The spawn of Kyuss by itself is CR 5, so be careful how many zombies you throw in alongside it, but this could be a very memorable "holy **** what the ****!!!" moment.

[Falcon X]

If you are willing to port monsters in From prior editions, here are some thoughts:

Eyes of a Blindheim
Horns of a Shocker Lizard
Rib bone of a Rusalka
Bottled Will-O-Wisp
Fangs of a Vorpal Rabbit
Finger of a Crawling Hand
Fur off a were-something (use were-rat statistics and pick, like a were-goat or were-sheep)
Freely given flesh of an intelligent undead (Find a Baelnorn, or maybe a necropolitan)

[Voltage89]

Cockatrice. The PCs might know about cockatrices, and they might agree because it sounds super easy as well as helping them, right? They're small, they're 1/2 CR, they have 11 AC and 27 HP, they're basically like chickens that can maybe petrify you, but how hard could they really be? Now, decide that the cockatrices in the area live in flocks. They find the tiny chicken monster they're supposed to hunt for parts and find that there are like a dozen of them right there and leaping at them.

Ettercaps. Sort of the same situation as above, only potentially way worse; you might even want to let them get in another level with another monster first. "A forest infested with ettercaps transforms into a gloomy place, choked with webs and infested with giant spiders, giant insects, and other sinister predators." Which means an infested forest could fit perfectly into your setting, but at CR 2, even a few of these things could be a problem, much less their insect posse.

Night Hag. Maybe they don't even need to kill her (she's CR 5 all by herself!). Maybe they just need her heartstone...

Jackals. They aren't bad at all, and neither is the jackalwere, which would be the actual star of this show. But maybe they're told they need a few parts from jackals, not even sounding like a big deal, jackals aren't even actually monsters... But maybe this pack of jackals is under the protection/jurisdiction of a jackalwere or two. For extra fun, this could even mean the players make an enemy of a lamia without even realizing it, if they kill her jackalwere servants (lamia are CR 4; you could bring one in shortly if you wanted!).

Manticores. Even two manticores would be a deadly challenge, while one would probably be fairly easy due to action economy, so be careful. Still, if they needed four manticore eyes... Or even just a single manticore tooth but found a pair, or even one and a child (just stat it a bit downward)... Or maybe just the one, but it serves orcs or hobgoblins and the players have to get through those somehow (battle or stealth) to get to it.

Mimics. Maybe they need to actually figure out how to find a goddamn mimic and get one of its teeth... or some of its drool. Finding it could be the hardest part, though going through a dungeon with the mimic actually being the treasure could be kinda funny.

Oozes. Similar to the mimic above. If you need to break off and put part of an ooze into a container, that could be kind of funny and very hard. A black pudding would be the most challenge, but a gelatinous cube is of course the ooze and might be fun for your players to figure out how to deal with.

Trolls. A troll is CR 5, and even a single one could be an issue for them, even with the action economy. Especially if you give it loathesome limbs, and if your players don't know about its weakness to fire. But still, it'll be memorable!

Flail Snails. I just really like flail snails, okay. If you have the players have to track down a couple of them, they can be a really unique fight. Plus, if they just need one shell so that the potion can be made, but run into a pair of them, a)a bit of a harder fight and b)they can use the second flail snail's shell to have three sorta-magical shields made (that can even be turned into spellguard shields later maybe), or a single robe of scintillating colors, if you want them to be able to get any of those things.

"A worm from a zombie." AKA maybe your players just think they're going into a little area that has an undead problem, and maybe it really is mostly regular zombies... except with a single spawn of Kyuss, from which they have to get one of the tiny green parasitic worms. The spawn of Kyuss by itself is CR 5, so be careful how many zombies you throw in alongside it, but this could be a very memorable "holy **** what the ****!!!" moment.
Thanks so much for all the info man! I'm a rather new dm but have played a good bit of d&d so all this help is greatly appreciated. I had ideas for a couple ruins scattered around the area which would work perfectly with the Ettercaps and Limia. Some of your ideas might be a little hard now, but once they level up I will definitely try them!