Horns seems custom-built for the Comic-Con crowd: It's based on the macabre 2010 novel by Joe Hill (Stephen King's son), it's directed by horror maestro Alexandre Aja (The Hills Have Eyes), and it stars Harry Potter himself. Daniel Radcliffe plays Ig, a small-town guy who sprouts devilish horns from his forehead and becomes the prime suspect in his girlfriend's (Juno Temple) murder. Yet those horns have a power that compels people to tell Ig the truth, no matter how horrible or hilarious. Hill describes the film as a ''tragicomic horredy,'' and Radcliffe, now 25, was drawn to the elements that tweak his famed alter ego. Ig wears Gryffindor colors, for example, and communes with snakes. ''It sort of plays into people's perception of [me] and slightly subverts that,'' says the actor. ''It's a joke within a joke, another layer for people who are in the know.''