Some TMNT stuff really isn't for little kids.
Dreadmon was a character appearing in the Teenage Mutant Ninja Turtles Adventures comics who later joined The Mighty Mutanimals. He was a South African native, who was sent away with his mother to Jamaica by his father, an outspoken opponent of apartheid, because he feared for their safety. Living in abject poverty as a teenager, he resorted to stealing. One night, he robbed a talisman from a wealthy Australian rancher who had been vacationing in Jamaica. To his surprise, the talisman imbued him with super speed, greatly bolstering his criminal career and figuring he would soon steal to the point of becoming the richest man in Jamaica. Unbeknowst to him, heavy use of the talisman had caused further transformations, and one night under a full moon the "puberty" of the talisman's magic had taken effect, whereupon he was transformed into a Tazmanian-devil like creature. After the talisman was recaptured, Dreadmon realized his mutation could not be undone, and stowed away on a fruit boat bound for Brazil.
Later, Dreadmon came across Jagwar and the Turtles as he returned to Tepui Valley in fear and terror (TMNT Adventures # 15). Dreadmon and Jagwar were eventually members of the superhero team the Mighty Mutanimals. However, during the "The Animus War" event Dreadmon and the other Mutanimals were killed by the Gang of Four on their secret island. Dreadmon and the other Mutanimals could only be buried. (TMNT Adventures# 54)
Dreadmon (like most other Mutanimals) has a cameo in Tales of TMNT Vol.2 #58 during a battle between the Turtles and Wild West C.O.W.-Boys of Moo Mesa against the cosmic super-beings Galactose, when during the battle several cracks across space, time, and reality appear, the Turtles catch a glimpse of their doppelgängers from other dimensions.