gooeylouie
First Post
No.
For the simple reason that the mechanics of the game simply don't support it - a creature that doesn't exist has no hit dice, no Str/Dex/Con scores, no movement modes, and no extraordinary attacks. You can't polymorph into a non-existent creature because there's nothing to polymorph into.
(Of course, you could, in theory, stat up such a creature, run those stats by the DM, and then polymorph into the creature... but that would depend on your DM agreeing to admit such a creature into his game.)
wouldn't the DM just make up the stats for the new creature on the fly?