The Zabulous Cosplayer is a rare Legendary Creature — Human Shapeshifter card from Unknown Event (UNK), collector number RZ04p.
As The Zabulous Cosplayer enters and at the beginning of your upkeep, choose a tournament-legal non-Aura permanent card at random. The Zabulous Cosplayer becomes a copy of that card, except it has this ability. (Use the "random card" feature on a Magic card search engine until you hit a permanent card.)