Old Hob is a one-eyed cat mutant, and the first major enemy of the Teenage Mutant Ninja Turtles in the IDW series. He was created by IDW's editor-in-chief, Chris Ryall. Old Hob has a gang of humans that work for him.
Old Hob was a stray cat that came across the Turtles and Splinter after they were dropped by the pair of ninja that had stolen them from Stockgen. The mutagen that was also stolen spilled and Old Hob came into contact with it, causing him to mutate. He tried to scurry off with a pre-mutated Raphael, but Splinter attacked, clawing out one of Old Hob's eyes. He would later mutate and team up with Baxter Stockman to get revenge on Splinter and the Turtles. Since the mutagen Old Hob came into contact was contaminated, he was sent to bring in the other mutants, dead or alive, in order to get mutagen samples from their blood. He was put in charge of a street gang and tried multiple times to take down Splinter and the Turtles.
A while later, Old Hob and his thugs come across Casey Jones and Raphael. Old Hob nearly killed them until the rest of the Turtles come to Casey and Raph's rescue. Upon remembering his past, Raphael went into a rage and almost beast him to death, but his brothers stop him.
Stockman was unhappy with his failure, but Hob claimed the money he was supplied wasn't enough to pay for forces strong enough to subdue the mutants, and that he would need an army to take them down. So to aid Hob Stockman gave him control of his Mouser robots. Old Hob used the Mousers to attack the Turtles, destroy their home and kidnap Splinter. Old Hob brings Splinter to Stockgen and is waiting for Stockman and General Krang when the lab is attacked by the Foot Clan and he is knocked out. Stockman believes that Hob's usefulness has run its course, so he shoots him.
Though thought dead, Old Hob appears alive and well at the end of Issue 16, where he encounters Slash on the shore of the water. The two team-up and vow revenge on Stockman and everyone else at Stockgen.
- Like Scratch before him, Old Hob's name stems from a colloquial name for the Devil.