When his family went for a vacation in the Hidden City, Raph chose to ask the Hidden City Police to bring him on a ride-along. However, the officers he approaches recognize his resemblance to notorious criminal Heinous Green, and instantly assume he is Green. They arrest him and he is thrown in a police van with the Mud Dogs—criminals who also are coincidentally similar in appearance to his brothers, and whose gang has a similar name to the Mad Dogs.
The Mud Dogs also assume Raph is Heinous Green, and when Raph realizes what's happened, he assumes the role for them of not only Heinous Green, but their leader, based on them being surprised that he has more brains than they had been lead to believe. Raph's "crimes" he sets them up to perform, however, are actually attempts to get them thrown back in jail—and ironically have the opposite effect to his intentions. When Raph tells the Mud Dogs to break into the police station and rob them, he assumes they'll be easily arrested, but instead, it goes off without a problem. When he takes them to the prison and tells them they can make a hideout there, he throws them physically inside, but they end up landing in a minimum security cell that is already padded out with luxury.
The Mud Dogs, however, tell Raph that they need to give a cut of their theft to Big Mama. Raph is not enthused with this idea, since he knows she will recognize him. The Mud Dogs convince him to come along, although he tries to hide his visage from her. She ends up seeing him, though, and tells them that he's not Heinous Green not only because she knows Raph from previous encounters, but because Green is right there in her office.
This leads to Green attacking Raph. Heinous Green was already larger than Raph, but he's capable of growing even further. While the "fight" is mostly Raph trying to get away, once Heinous Green reaches kaijū size, Raph realizes he needs to fight back and summons his giant Smash Jutsu aura, finally beating the criminal down.
Raph turns over Green to the police, who apologize for the mistake, however, they then again mistake him for a different criminal, Evil Emerald, and throw him in a jail cell.
- Although the Mud Dogs were voiced by their previous series Turtles counterparts (Seth Green, Rob Paulsen, and Greg Cipes), Heinous Green—who is the only one of the equation that isn't actually a Mud Dog—only communicated in growls and is not credited with an actor.
- However, it is unknown if Green is able to speak.
- With his dōgi and hairstyle, Heinous Green greatly resembles Heihachi Mishima of the Tekken fighting game series.