In the IDW comics, Slash was introduced as Specimen 6, a snapping turtle experiment at StockGen mutated with Old Hob's DNA assigned to hunt down the Ninja Turtles and Splinter. However, his mind became unstable and gave him a savage nature, so Specimen 6 was contained in a special tank guarded by the Rock Soldiers. He was later freed due to April O'Neil's diversion to retrieve the Turtle Tracker for the Ninja Turtles. After punching one of the Rock Soldiers, he escaped from the lab into the night. From then, Slash began lurking around the city as a mindless monster injuring people and damaging their property, such as attacking Michelangelo's pizza-delivering friend Woody and leaving scratch marks on April's van. After ripping off the shirt of a thug the Turtles just apprehended, he followed them to an abandoned church and attacked them in the church basement. Though proven more powerful than the Turtles, Slash was accidentally impaled by Leonardo and left to fall into the sewers. He eventually survived the wound and was washed ashore to be woken up by Old Hob, who told him that they should work together to hunt down anyone with a connection to StockGen. Slash was shown the error of his ways when Michelangelo gave him a candy bar that he instantly fell in love with. He agreed to help the Turtles escape from one of Shredder's traps. He was an integral part of a mission to reclaim Leonardo from the Foot Clan, and developed a strong antipathy towards Hun, whom he knew as the "Dragon Man." At the mission's conclusion, he was given a new black mask by Leonardo, as well as a bladed gauntlet. Slash's life changed forever when Hob began producing new mutants, but discovered that Lindsey Baker's psychotropic compound was crucial to the process. He took a syringe of Splinter's compound-infused blood, declaring that he wanted to be a "hero" like Michelangelo. Mikey tried to reassure Slash that he himself was not even a hero and that the two of them were both still just children, but Slash injected himself anyway. After a few minutes of agonizing pain, he suddenly began to think more clearly and speak more eloquently than before. With his new intelligence, he became the co-founder of Hob's new mutant army, the Mutanimals, and was involved in Hob and Splinter's attack on the Foot Clan.
