Characters that can freely transform the shapes of their bodies to assume different identities, for impersonation purposes, or otherwise.
Take note that you should not add characters that can only slightly modify their forms through external power-ups (such as Mario), ones that simply mutate over the course of a storyline (such as Acacia from Toriko), or ones that have limited or uncontrolled transformations (such as Saiyans from Dragon Ball, or werewolves from folklore).
For the kind of characters that do qualify, examples include Mystique from the X-Men, or Ditto from Pokemon.
For the ones that don't, please use the Transformation Users category instead.
Help with replacing any inaccurate entries is very appreciated.