Some TMNT stuff really isn't for little kids.

The Purple Dragons (or Purple Dragon Gang) are a fictional New York street gang, in several of the Teenage Mutant Ninja Turtles continuities. The Purple Dragon Gang are from the Lower East Side in New York City. They are the toughest gang on the East Side. They often are led by Hun and have some connection to The Shredder, though not always. They are particularly known for their salient transition icon, the image of a purple dragon, which they wear as either a tattoo or on their clothes. They mostly commit robberies and threat people.

The Purple Dragons appear in the 1984 Mirage Comics. The Ninja Turtles fight them in the first issue of the original comic in a situation in which the Turtles have their first major skirmish on the surface. In this issue The Purple Dragons insult the Turtles repeatedly, and discover that their guns and knifes are useless against their martial arts. Eventually, the Turtles manage to kill most of them before the police arrive.

The Purple Dragons appear again 25 years later in 2009 in Tales of the Teenage Mutant Ninja Turtles #56. Decades ago, the gang's leader, a man named Hunter Mason (the true identity of Hun), who until then was known from the cartoon series from 2003, delivered a brutal beating to a teenage Casey Jones, one of the Purple Dragons bitterest enemies, prior to being thrown in jail.

The leader of the “Black Dragons”, apparently cut a deal with Officer Miller which resulted in Hun being locked up and allowed him to gain control of the Purple Dragons. He then helped the Purple Dragons’ one-time-rival, the Shredder, wipe out the group turning them into the Black Dragons: a gang subservient to the Foot Clan. After being released from jail, Hun wiped out the Black Dragons and declared his intentions to rebuild his criminal empire.