Crablante

Crabrante is a creature which was formed when a person ate too many crabs and underwent metamorphosis.

Appearance
Crabranate is a large creature with large, crablike claws and a hard carapace covering his upper body, while his lower body seems to be the same as a large males, with underwear on. He has two holes on his head that act as a nose, a rather normal mouth, and two eyestalks that protrude on the side.

Personality
Crabrante seems to have turned into a bloodthirsty monster after he turned into a crab, as he killed several people on his search to kill a boy who defiled his body with permanent marker. When talking, he occasionally adds 'Blubblub' and 'lol' to the beginning and the end of his sentences, a verbal tic that indicates he is a crab that was once a man.

Plot
Crabrante appears before Saitama three years before the main storyline. They meet in the middle of a crowded street. Crabrante's appearance causes everyone apart from Saitama to run away from him in terror. He asks Saitama why he isn't running away from him like all the others, Saitama replies that since he is unemployed and unable to get a job he feels that nothing really matters anymore and thus he doesn't really feel like running away. At hearing this, Crabrante chuckles and says that Saitama's lifeless eyes remind him of his own and since he is after a different target anyway, a child with a cleft chin, he is willing to let him live and goes away.

Crabrante later appears in a park and discovers the child with the cleft chin. Just as he is about to kill him the boy is saved by Saitama, who is also present there. It is revealed that the reason Crabrante wants to kill the child is because he drew nipples on his body with a permanent marker while he was sleeping in the park. He tells Saitama to not get in his way or he will kill him too, hearing this Saitama starts laughing which confuses Crabrante. Saitama reveals that Crabrante reminds him of a villain from an old anime that he used to watch in his childhood and that his childhood dream was to become a superhero who could beat villians like Crabrante with one punch. After a tough fight Crabrante is defeated by Saitama.