When the Pokemon uses a move and does damage, the Pokemon's type becomes that type gaining STAB. The attack has to be successful, so misses or Protects won't count for this ability.
Who gets it: Mr. Mime, Jynx, and Gothitelle. All of the Pokemon that get this ability are Pokemon that look like they could be actors or actresses.
An example of this move in play is: Mr. Mime has Thunderbolt, Magical Leaf, Shadow Ball, and Psychic. Mr. Mime uses Shadow Ball and turns into the Ghost Type and is immune to Fighting. --- Sister-How would you feel if you were playing a game, and in that game, Mario was a baby? Me-I'd be playing Yoshi's Island, so I would be feeling great.