In the 1987 Teenage Mutant Ninja Turtles cartoon, Bebop was a human thug before mutation.
Bebop was one of the street criminals recruited by Shredder and transformed into a mutant warthog. His partner, Rocksteady, was likewise a human thug who became a mutant rhinoceros. The pair function as Shredder’s recurring comic-relief henchmen.
Their animal forms are central to their identities, but neither character began as an animal. That origin also differs from some later continuities, which alter details of their human lives or their relationship with the Foot Clan.
The cartoon’s mutation sequence helped establish the familiar duo for generations of viewers. Bebop and Rocksteady are often remembered together, but they are distinct characters with different animal forms.