Race: Artificial Mutant
Gender: Male
Abilities: Weapons; Mole Hands
Level: Tiger
Affiliation: House of Evolution
Debut: Chapter 8/Episode 2
Ground Dragon was an artificial mutant created by Dr. Genus at the House of Evolution. He's basically a massive black mole with white kanji markings across his body spelling out his own name—pretty on-the-nose design. His most notable feature beyond that is a pair of massive claws.
As for personality, there's not much to say since he didn't stick around long enough to establish one. Saitama killed him so quickly that fans never really got a sense of what he was like beyond being another one of Genus's creations sent to fight.
Content compiled by AnimeList.moe from publicly available sources.
