Comet Guy

Comet Guy was a human superhero from a distant planet called Mertz, a planet populated (almost) entirely by superheroes. He possessed the ability to shoot fireballs from his hands, fly and move at incredible speeds. He could also travel through outer space by (somehow) squeezing his entire body up inside of his helmet, which could fly.

Comet Guy was not particularly intelligent and was quite clumsy, and whenever he heard the ringing of a bell he would spontaneously begin to dance against his will. Upon hearing a whistle, he would snap back to his normal self. For this embarrassing weakness, Comet Guy was banished from Mertz.

He came to Earth to become its protector, and was tricked by Steelbeak into helping FOWL by getting rid of Darkwing Duck, whom Steelbeak claimed was really a villain. Eventually however Darkwing convinced Comet Guy that Steelbeak was tricking him, and, with Darkwing's help, Comet Guy turned his weaknesses into strengths, defeated FOWL singlehandedly, and returned to Mertz as a worthy hero.

Later, Comet Guy returned to Earth to seek Darkwing's help. He and the other heroes on Mertz had misplaced Mertz's only non-superpowered citizens, Ordinary Guy, whom the various superheroes took turns rescuing. Comet Guy and his fellow superheroes wanted Darkwing, as a hero without powers, to be the new Ordinary Guy. During his time on Mertz, Darkwing, as the new Ordinary Guy, attempted to liven things up by convincing Comet Guy to pretend to be a villain and be the one to endanger him. But Comet Guy's heart wasn't in it, and he saved Darkwing from his own death trap.

Eventually it was revealed that Ordinary Guy had actually grown angry with constantly being bothered by his superpowered neighbors, and had turned evil and invented a machine which stole all of the heroes' powers and bestowed them upon himself, transforming him into Extraordinary Guy. Darkwing however defeated him and reversed the effect of the machine, returning Comet Guy's powers.