Alrighty, while looking around the polymorph school, I tried find good selections for the Undead Anatomy and Monstrous Physique spells. Thus far, after looking over all the monsters of each type, here is what I've found...
Monstrous Physique 1
Witchwyrd - 4 slam attacks is pretty good stuff, and darkvision is a nice bonus too.
Sabosan - 1 bite, 2 claw attacks, and the ability to fly with darkvision. Never really a bad choice.
Popobalav - okay...this guys just seems unfair: 1 bite + 2 talons + 2 wings + climb + fly + darkvision. sweet mercy!
Monstrous Physique 2
Calikang - Yeah...4 slam attacks plus 2 spare hands to wield weapons...that's pretty sick.
Undead Anatomy 1
To be honest, I couldn't find anything really that good to transform into. I mean, at the very least, you get 1 bite and 2 claw attacks when u use the spell, so if u can find something with a fly speed, then that would be great (sadly i could not)
Undead Anatomy 2
Again, couldn't find anything all that great. If anyone has suggestions, let me know
That's about all my research has yielded. Sadly there was no real reason to use Monstrous Physique 3 or Undead anatomy 3 because aside from the extra reach and size bonus...there really isn't any form i could find that was worth transforming into. if someone wants to add a little more insight, I'd greatly appreciate it.
Various undead types are also templates. So you could encounter a vampire harpy, for example. The trick is that you need a piece of the creature you turn into as a material component. So you're boned unless at some point your DM pits you against what you want to polymorph into.
Also, I'm pretty sure that by RAW you do not get extra attacks from these types of spells. They explicitly list what benefits you get. This is a departure from the 3.5 polymorph cheese.
Monstrous Physique 1: Chardal. 4 claw attacks, plus bite, a swim speed, and it scales. This forms offers more abilities as your Monstrous Physique level increases...Overwhelming, Cold Vigor, and eventually, a breath weapon.
Charda, even...stupid typo
I still think that the Popobalav kinda takes the cake for Monstrous Physique 1. I mean, it's so strong that it almost makes me wonder if the bloody thing is even a legal target.
Seriously...5 natural attacks and a fly speed *gawks*
but yea, Eschew Material component feat can get u out of the 'piece of creature' stuff...still, i do find it kinda cheesy that you can transform into something that you have never encountered. I wish they would put that restriction on polymorph as well (then again, that is a pretty harsh restriction...but who's to say that you can't just go to some library and do some 'research' on a creature in there)