Shapechange can be similar to the Manggus' ability, without the exceptions.
Stripping out the exceptions:
Change Shape (Su): Monkey can assume the shape of (any?) creature. The creature’s hit dice cannot exceed twice Monkey's hit dice. In a different form, Monkey gains all the extraordinary and supernatural abilities of that form. Monkey can remain in a form until he chooses to assume a new one. A change in form cannot be dispelled, but Monkey reverts to his natural form if killed. A true seeing spell or ability reveals his natural form.
Change Shape (Su): A manggus can assume the shape of any Medium, Large, or Huge creature. The creature’s hit dice cannot exceed twice the manggus’ hit dice. The new form must be a creature that the manggus has personally seen. In a different form, the manggus loses its natural attacks, but gains all extraordinary and supernatural abilities of the new form. A manggus can remain in a form until it chooses to assume a new one. A change in form cannot be dispelled, but a manggus reverts to its natural form when killed. A true seeing spell or ability reveals its natural form. If the manggus takes fire damage from any source, it is immediately forced back into its natural form.
Stripping out the exceptions:
Change Shape (Su): Monkey can assume the shape of (any?) creature. The creature’s hit dice cannot exceed twice Monkey's hit dice. In a different form, Monkey gains all the extraordinary and supernatural abilities of that form. Monkey can remain in a form until he chooses to assume a new one. A change in form cannot be dispelled, but Monkey reverts to his natural form if killed. A true seeing spell or ability reveals his natural form.