[3.5] Looking for more powerful Polymorph forms

[Arathorn]

My DM is letting me use a prestige class that gives me the ability to access forms that polymorph can't normally utilize. The problem is that most of the polymorph threads naturally don't cover monsters of these levels. I would appreciate it if you could give me some help in finding some good forms.

The notable advantages are: 1) I can make use of forms with the Outsider or Elemental templates 2) the cap on hit dice has been increased (I'm specifically looking for forms between 16-26 HD) and 3) when I finish the class, I will get access to all extraordinary and supernatural attacks and abilities while transformed (but not spell-likes) , even those normally not possible while casting.

With these three changes in mind, what great new forms are now viable?

[Kraken]

This sounds like the class basically turns polymorph into shapechange. I'm not a person who bookmarks things, but I'd look for, or wait for others, to post shapechange guides, and that should pretty much do the trick. Shapechange does cap at 25 HD instead of 26, but I'm not sure that'll cause you to miss out on anything.

[Venger]

here (http://brilliantgameologists.com/boards/index.php?topic=3689.0) is a good place to start.

[Arathorn]

Those actually look quite good. I've ha a hard time finding shapechange guides for some reason.