Crabrante

Crablante was a Tiger-level Mysterious Being, originally an ordinary human who transformed into a crab monster after eating far too much crab. He was killed by Saitama.

After his transformation, Crablante became a genuinely bloodthirsty monster, massacring people in his hunt for a boy who had vandalized his body with a permanent marker while he slept. Fiercely proud of what he considered his beautiful new form, he turned violently aggressive toward anyone who defiled it — yet he showed real compassion toward a depressed, pre-hero Saitama, sparing him after recognizing the same lifeless look in his eyes that he carried in his own. Years later, that same target — the Ball-Chinned Kid — became the reason Crablante and Saitama crossed paths again.