Chameleon was a character from the Teenage Mutant Ninja Turtles Adventures comics issue 9. He also appeared in a children's book. He was once a human spy known as the Chameleon, who has stolen some classified weapons plans.
The double-agent was fleeing from the police. To make his escape, the spy heads down into the sewers, and as Fate would have it, he arrives at a crossroads where he runs into both the TMNT and Bebop and Rocksteady! Rocksteady nabs Chameleon, and as the Turtles prepare to bonk heads, a Foot soldier shows up on a Knucklehead. The contraption proves to be enough of a distraction to allow Bebop and Rocksteady to escape with the Chameleon.
The two bogus baddies haul the agent to the Shredder, who wants the plans that Chameleon has stolen... but the spy doesn't have them with him. Shredder demands the secret documents, so Chameleon offers to sell them to the villain... but this only angers Shredder. The nasty ninja brings out a real live chameleon and a spray can of mutagen, explaining to the double-agent that if he doesn't reveal the hiding place for the plans, he will be turned into a mutant. Chameleon complies with Shredder's demands, and Bebop and Rocksteady hurry off to retrieve the weapons blueprints. Shredder, being a dastardly villain, decides to mutate Chameleon anyway! But once he is mutated, Chameleon changes his colors and makes his escape.
Chameleon retrieves the plans from their hiding place and makes another escape! The blueprints were than mysteriously returned, with a note pinned to them saying "Some things are not worth profiting from." As the issue ends, we see the mutated Chameleon watching the report from outside a department store window, grinning.