"IT" was particularly scary for me because i've been working on serial killer profiling and the character is based off of the serial killer John Wayne Gacy who met with Stephen King after he was convicted.

John Wayne Gacy used to dress up as a clown and go to children's parties in the neighborhood and then stalk the victims he found there. Later on he would rape and murder them, then put their bodies under the floorboards of his home. There were 30 counted bodies, it remains a mystery how many he threw into the river because he had a habit of speaking in riddles to the jailers. He was put to death in the '90s in a botched execution that was never investigated. It remains uninvestigated because he was so hated, except by many in the public who became his followers.