Is this a known combo? (Dragon familiar abuse, am I reading this right)

[Soranar]

Ok so a dragon familiar grants you a wyrmling as a familiar

said wyrmling (if it's a gold dragon or another one with alternate form) can turn into any small or medium animal and humanoids

so it can turn into a legendary ape (30 STR)

it also specifies that a dragon capable of turning into a humanoid shape is proficient with simple weapons so it could use something like a longspear two handed

that seems way better than any animal companion I can think of

[sleepyphoenixx]

It's still just a wyrmling dragon familiar, meaning it still has only half your hp (which isn't much if you're a wizard) and your low BAB.
So it sounds nice, but it's really no more impressive than a half-health wizard with 30 STR, which isn't very, especially at the level where you qualify for a gold dragon wyrmling familiar.

[Soranar]

I was thinking of using a hexblade, duskblade or even a ranger with the urban companion ACF

that means full BAB and half a reasonable amount of HP (3/4 in the ranger's case)

not bad compared to an animal companion though it'll cost 2 feats

[Coidzor]

Ahh, for a moment I was thinking the Pervirtuoso (http://www.giantitp.com/forums/showthread.php?178713-Familiar-Abuse/page2)had been reborn.

It's not the most talked about, but it's come up a few times. Doesn't really have a name, and gishes are generally a bit feat-starved (partially because of needing to qualify for gish PrCs), so spending two feats to get a second fighter to gear up isn't always the best, especially when there's Leadership or Dragon Cohort for a Steel Dragon or the like.

[Grod_The_Giant]

I was thinking of using a hexblade, duskblade or even a ranger with the urban companion ACF

that means full BAB and half a reasonable amount of HP (3/4 in the ranger's case)

not bad compared to an animal companion though it'll cost 2 feats
Ranger would theoretically be the best choice, but you don't have an arcane caster level-- you'd need Sword of the Arcane Order and 14 levels of base Ranger, or 12 levels of Shooting Star Ranger, or 10/8 and Practiced Spellcaster. That's three feats (albiet one you'd probably want to take anyway) for a combo that comes online at 9th level, by which point I think the resources/effectiveness ratio is starting to swing against you.

[Thurbane]

The fault is with Legendary Animals: they should have the Magical Beast type, IMHO.

[Rebel7284]

Some notes:
- Hit Points: One-half the master’s total or the familiar’s normal total, whichever is higher. (Draconomicon, p. 141)
So the familiar's HP may well be higher than the master if you do take it on a wizard.

- I believe, based on the wording of Sword of the Arcane Order, that it does not make Ranger into an arcane spellcasting class. It remains a divine spellcasting class with the ability to cast arcane spells from those divine slots. Similar to a cleric with Anyspell.

[sleepyphoenixx]

I was thinking of using a hexblade, duskblade or even a ranger with the urban companion ACF

that means full BAB and half a reasonable amount of HP (3/4 in the ranger's case)

not bad compared to an animal companion though it'll cost 2 feats
That's a little better, but you're still paying 2 feats for a third-rate warrior (worse than fighter), at a level where pure melee has significant difficulty keeping up (gold wyrmling requires ECL 14 iirc). And still only half your HP, which is still not that much even on a d8 or d10 HD. A familiar will pretty much always be fragile, just by the nature of the 1/2 master's hp.
It's not enough for me to be comfortable sending the resulting XP-bomb into melee combat, because chances are it'll die, cost you XP and then make your 2 feats useless for 1 year of ingame-time.
Pretty much every aspect of familiar mechanics discourages sending them into melee. You can make them work that way if you really want to, but it's definitely not cost-effective.

Edit: the Urban Companion ACF on a ranger is the exception, assuming your DM lets it qualify for Improved Familiar. It lacks the XP cost on death and you can get a new one in 24 hours, which is the main hurdle for sending familiars into combat. Not to mention that a ranger's regular animal companion is utter trash for pretty much anything.
It'll still be rather fragile compared to a well-chosen (druid) animal companion, but it'll have higher BAB and intelligence to make up for it.

That's the big difference compared to an animal companion.
That one comes combat ready pretty much for free. If it dies you can summon a new one in a day, it doesn't cost you feats, it comes with a good buffer of hp, size, natural attacks and so on.
You just slap some buff spells on it, maybe buy some cheap items and it'll work fine as a meatshield without wasting any significant amount of your build resources.


Some notes:
- Hit Points: One-half the master’s total or the familiar’s normal total, whichever is higher. (Draconomicon, p. 141)
So the familiar's HP may well be higher than the master if you do take it on a wizard.

True enough, 126hp is quite a bit for a wizard (gold wyrmlings have 68hp), at least unbuffed. That's still a very tiny amount of hp for a primary melee character at level 14+.