The inspiration for Pennywise came to Stephen King while crossing a covered bridge and his mind went to goat gobbling troll in the "Three Billy-Goats Gruff." He explained how the idea struck him while walking past a sewer after a rainstorm, "As I looked at this one sewer [...] the voice inside speaks up and says, 'The troll lives there too, only when he's in the sewers he has a clown suit."'