FightingMario54321

FightingMario54321, whose username is often abbreviated to FM54321 or FM, is a YouTuber, as well as one of SuperMarioGlitchy4's close friends. He used to be a Super Mario 64 machinimist and blooper maker, but he decided to quit that game in March of 2015. His debut in SMG4's bloopers was SMG4 VS. SMG3, in  which he beats up  SuperMarioGlitchy3; since then he has appeared in several other videos of SMG4's. Good at fighting – hence his pseudonym – FightingMario54321 is somewhat the tough guy, and acts as one of the few sane characters. Like Nintendofan997, he will be confirmed by daveg502 very soon.