Kurr

Officer Dragon, real name Kurr, is the protagonist of Erik Larsen's The Savage Dragon comic book series. After being found nude in a burning Chicago field by Lt. Frank Darling, the green-skinned, fin-headed amnesiac is given the name "Dragon" and recruited to the Chicago Police Department. It is later revealed that before being found on by Darling, Dragon was a genocidal and tyrannical alien warlord named Kurr, who had his people stage a mutiny against him, giving him brain damage and dumping him on Earth.

TMNT Crossovers
Officer Dragon had crossed over with the Teenage Mutant Ninja Turtles several times, most of which occurred while the Turtles were being published under Image Comics' label.