Good 7 HD creatures to become?

[Voidstar01]

I recently acquired a psychoactive of proteus (ML7 metamorphosis effect), so what're some good things to become with it?

[Biffoniacus_Furiou]

The Polymorph Handbook (http://minmaxforum.com/index.php?topic=519.0) should cover what you need.

Consider getting it at a higher ML for better forms. RAW, the Psychoactive Skin of the Proteus always has the same price and always has the same crafting cost, but "the caster level is determined by the creator (http://www.d20srd.org/srd/magicItems/magicItemBasics.htm#casterLevel)" applies to manifester level as well. So if the person who created that item had a manifester level of 15, they could have made the item with that manifester level. An item's printed caster/manifester level is the default for when that item is discovered as loot, but a crafted magic item can always have it set higher.