Mr. S. Cooper is the man who owns a carnival whose patrons were being murdered.
Mr. Cooper runs the Cooper Carnivals. Previously, he was the lot manager for Bunker Brothers. He gives Sam and Dean a job in his circus. Little did he know that in his circus, the blind man was a monster who dressed up as a clown to get to kids so he can eat their parents.
While investigating the trailers, Sam checks out Mr. Cooper's, and runs into him. Mr. Cooper promptly considers him a "Peeping Tom".