Some TMNT stuff really isn't for little kids.
Monsterex is a monster from Teenage Mutant Ninja Turtles Adventures by Archie Comics. He is a two-headed combination of a werewolf, vampire, gill-man, mummy, and Frankenstein's Monster. He has all their supernatural powers, as well as the weaknesses against Sunlight.
Monsterex is created when Krang blasts the Ninja Turtles television with a mutating ray. The ray interacts with the monster movie they were watching and creates the strange patchwork monster out of thin air. Though the turtles attempt to stop this threat before it can begin, Monsterex proves too strong for them and escapes. The turtles follow in pursuit and with the aid of Bookwurm, head to the Magic Castle amusement park in New Jersey where they suspect the monster will be.
The turtles are again bested by the incredibly powerful Monsterex and are only saved when the approaching rays of sunlight come with dawn. Monsterex retreats as the turtles celebrate their lucky victory.
Months later, the turtles visit the amusement park again on Halloween. With Splinter and their friend Ninjara in tow they wander through the wax museum only to find Monsterex frozen in mud. Donatello accidentally knocks Monsterex over, freeing the enraged creature. Monsterex leads the turtles on a chase through the populated amusement park with patrons believing that all of the strange mutants are merely people in costumes. Again, dawn is their saving grace when Monsterex takes refuge in the hall of mirrors. With a simple smash of the skylight, sunlight floods in and melts Monsterex into a puddle of water.