Some TMNT stuff really isn't for little kids.
Bebop and Rocksteady appear (first in human form) in the IDW comics, where they also used to work for the Shredder and the Foot Clan. In their first appearance they were helping the mutant Alopex, find the secret hiding place of the Ninja Turtles, but by the distrust of Raphael they were eventually thwarted. Finally, both voluntarily adhere to the transformation to their mutant forms, in order to join the ranks of the Foot.
Their origin was finally explained in their villain micro. Bebop was a gang member. After he and his buddy Rocksteady were kicked out of their gang they joined the Foot Clan and defeated a bunch of other gang members for the honor to become mutants. Rocksteady became a mutant rhino while Bebop became a mutant warthog. After screwing up a job and thinking Karai to be dead, Rocksteady suggests that since Karai is dead, they return to Foot Headquarters and just say that she deserted. Karai isn't dead, however, and has overheard the entire mutinous conversation. She sends a bunch of Foot Ninja to kill them. However Rocksteady and Bebop defeated them and ask for a second chance. Karai than decided to keep them due to their brute strength.
The two mutants were debuted before the Foot Clan near the end of the City Fall arc, when Karai summoned them as reinforcements during a battle with the Turtles. They successfully drove back Splinter, Michelangelo, Raphael and Donatello, but were defeated by April using an antigravity gauntlet. They attempted to pursue, but were driven back by a grenade.
Bebop and Rocksteady were later recruited by Pigeon Pete, who thought they might be good additions to the Mutanimals. However, Hob reacted badly when he saw them, both because they were part of the Foot and because they were originally human. A massive fight broke out between Rocksteady and Bebop and the various other mutants, including Alopex, Michelangelo and Splinter.
They were assigned a more deadly duty in the Attack on Technodrome arc, in which they were assigned to watch over Donatello while the Foot Clan attacked Krang's forces. When Shredder realized Donatello had tricked them, he ordered the two mutants to murder the Turtle. They savagely beat Donatello, breaking his shell open and leaving him for dead.
Bebop was one of the Foot Clan representatives during the Gauntlet, along with Rocksteady, Koya and Bludgeon. He fought Michelangelo, but the Turtle used agility and tactical thinking to pit Rocksteady and Bebop against each other. When Splinter became leader of the Foot Clan, Bebop departed for parts unknown.
Bebop and Rocksteady became the center of the Bebop and Rocksteady Destroy Everything miniseries, in which the Turtles find the skeletons of their mutated foes in a museum's prehistoric exhibit. Meanwhile, the present-day Bebop and Rocksteady are in Rio de Janeiro, repeatedly failing to join other gangs. They come into possession of a time scepter and accidentally activate it, causing massive disruptions in time and between different realities.
- Teenage Mutant Ninja Turtles Micro-Series issue 1
- Teenage Mutant Ninja Turtles Micro-Series: Villains issue 4
- Teenage Mutant Ninja Turtles issue 25 (IDW)
- Teenage Mutant Ninja Turtles Micro-Series: Villains issue 7
- Teenage Mutant Ninja Turtles issue 27 (IDW)