Rocksteady (Batman/TMNT)

Rocksteady is a mutant rhinoceros who, along with his friend Bebop, work for the Foot Clan. After the arrest and imprisonment of the Shredder, Rocksteady and Bebop took over a faction of the splintered Foot Clan, due to their immense physical strength.

However, their dominance was disrupted when Bane arrived from a different dimension, and united most of the Foot behind himself. He demanded the pair's allegiance, and after a moment of hesitation, Bebop and Rocksteady knelt in front of him. They then served Bane, first by bringing him Baxter Stockman and then by being test subjects for a new variety of Venom that Stockman synthesized.

Newly enhanced by their "juice," the pair were unleashed on Batman, Robin, Splinter and the Turtles. They quickly proved that their already-considerable strength was massively enhanced by Venom.

They accompanied Bane to Liberty Island, where they corralled the citizens of New York to serve their new leader. However, Donatello soon blanketed the island with a gas that flushed Venom from its users' bodies, reducing Bebop and Rocksteady to their usual level of strength. They remained at Bane's side until Donatello successfully knocked the villain out, at which point they claimed to have been working to help Shredder bring down Bane. They are last seen being loaded into the Turtle Van.