Good 12HD suggestions for Shapechange

[TheGogmagog]

Wyvern is one of my recent favories, I am making plans to use it at 15th level polymorph even though it's only a 7 hd creature. Aside from that Leonal? (eladrin?) perhaps has outrageous abilities, It's HD might be 15 though.

I was thinking a rogue in roper or hyda form would be painful. A lot of sneak attacks at thier highest attack.

But can you polymorph/shapechange into a creature that has been advanced to the number of HD you can have? I would assume the answer is no, but thought I would check. If so, a Wyvern advanced to 12 HD has got to be the best attack form.

 

[TheGogmagog]

If you get (SU) attacks, there is an invevitable that starts with M. It has vampiric touch special attack, you could run your HP up to whatever you want with cooperation with an ally and wand of cure light wounds. It's other SU attack is enervation ray.