Henry Bowers was the secondary antagonist of It. He was the Losers' arch-rival and Pennywise's former henchman.
After being humiliated by the seven main characters known as the "Losers Club", Henry's sanity begins to finally deteriorate, with a final push from It. He and two other greaser bullies named Victor and Belch, followed them to the sewers to kill the Losers as revenge. However, the three become lost in the labyrinth tunnels of the sewer and in the process Vic is decapitated and Belch's face is mutilated by It in the form of Frankenstein. Henry is able to escape by running as fast as he can out of It's reach. He finally makes it out of the sewers but his hair has turned completely white by the horror-shock of seeing his two friends murdered and seeing It in its true form, which also drives him completely insane. After several nightmarish hours of aimlessly staggering, he finds his way back to his home. At his home, he finds the police, who have just found his father's corpse, whom he himself killed with a switchblade under It's possession. The police assume that the now severely crazy Henry, has committed all the murders that year (perhaps under It's influence). And Henry is found guilty and immediately placed into Juniper Hill mental asylum for the rest of his life. 30 years later, Henry is a middle-aged man still locked up in the asylum. When Pennywise returns he manipulates Henry to kill the main characters and helps him escape the institute where he tries to kill a now adult Mike Hanlon, the only African-American member of the club. When other adults from the Losers tried to save Mike, Henry accidentally stabbed himself with his switchblade in the process, and died.