Cleon
Legend
Oh, I thought we were just doing Alternate Form. Anyway, let's just go with those 2; if it wants to keep it's (potentially) better physical abilities, it can use Change Shape.
Fine by me.
We should add Giants and Monstrous Humanoids to the allowed forms, since it mentions they can imitate an annis hag.
How's this:
Alternate Form (Su): A uran doppelganger can assume the form of any Small, Medium or Large Giant, Humanoid or Monstrous Humanoid.
Change Shape (Su): A uran doppleganger can assume the shape of any Small, Medium or Large Giant, Humanoid or Monstrous Humanoid it touches. Urans using Change Shape can also mimic any equipment their target is carrying (see Mimic Equipment, below). If used in combat, this special ability requires a successful touch attack which does not provoke an attack of opportunity. An uran doppleganger can remember the shape of anyone it has previously duplicated, and recall that duplicate shape at will.