After this humiliating setback, The Shredder developed a plan to defeat the Turtles by mutating members of the street gang that Rocksteady and Bebop are a part of so that they would have abilities greater than the Turtles'. Rocksteady and Bebop both volunteered to undergo the procedure first (though neither was particularly aware of what it would entail) with the promise that it would allow them to exact revenge on the Turtles. As the result of being brought into contact with a common warthog and a black rhinoceros that Shredder had abducted from the zoo, Bebop mutated into a humanoid mutant warthog while Rocksteady mutated into a humanoid mutant black rhinoceros.