This elf predicts both it and bard would probably be the winners in the pick a skill tree, and polymorpher has quite a lot of potential for those who want to be good ol' shapeshifters (or druids (mixing geomancer with polymorpher would definitely yield that pretty well)). So what kinds of skills do you think a polymorpher has? I have a few ideas I can share.
Forms: Probably acquired as different skill books (I.E. Zombie, Troll, Crab). You would pick up the racial skills in exchange for your own by transforming into a different species. Would benefit both rogues and warriors. Using a mouse to slip by or provide recon for the rest of the party and then turning into an orc to crush them! Mwahaha!
Wings: Small additions onto a character like this for a temporary amount of time could provide some tactical advantage. With wings, you could soar over land hazards, yet still be vulnerable to gasses.
Claws: Who needs a sword when you are your own weapon?! Or maybe clawed feet to give temporary immunity to tripping.
I think one of the devs mentioned being able to sprout tentacles for extra melee reach. But share your ideas! What do you think a polymorpher should have?