Lucy is a disguise used by Monkey D. Luffy in One Piece during the Dressrosa arc. To enter the Corrida Colosseum and compete for the Mera Mera no Mi, Luffy adopts the alias "Lucy" and a gladiator persona. This identity helps him participate in the tournament, meet allies, and confront enemies while hiding his true name. The character is not a separate person but an important temporary role that advances the Dressrosa storyline and Luffy's efforts against Doflamingo.