Monkey D. Luffy

Monkey D. Luffy (モンキー･D･ルフィ, Monkī D. Rufi), also known as Straw Hat, is a pirate and the main protagonist of the manga and anime series One Piece written by Eiichirō Oda. He is the son of the Revolutionary Army's commander, Monkey D. Dragon, the grandson of the famed Marine, Monkey D. Garp, and the adopted brother of the late "Fire Fist" Portgas D. Ace and the revolutionary Sabo. His lifelong dream is to become the Pirate King by finding the legendary treasure left behind by the previous Pirate King, Gol D. Roger. As a child, he accidentally ate the Gomu Gomu no Mi, causing him to become a rubber boy.

Assist Trophy rumor
On October 17, 2010, SSF2 Developer Geno posted a fake screenshot of Luffy using his Gomu Gomu no Baku Baku  (ゴムゴムのバク バク) against Ness, leading fans to assume that he  would appear as an Assist Trophy in the Super Smash Flash 2 Demo 0.7 (which he did not appear in.) The screenshot, while fake, actually used coded data to feature rendered sprites of Luffy in-game.

Controversy
During the livestream of Apex 2014, many fans disputed in chat about Luffy being in the game. Many also argued that there were other characters they would pick over him. Another user posted a fake image they had found on the wiki, which caused many others to believe he was "leaked". The slots were revealed to be and. It would ultimately be revealed that the developers had no plans to add Luffy or any other anime character into SSF2's roster, citing the backlash already present from Ichigo, Naruto, and Goku's presence as playable characters.