Mr. Hammerstone is the PE Teacher at South High. PJ was annoyed when he wouldn't let him graduate at first. He explained that he had to master the art of squaredancing by the last day of school. Hammerstone also has a habit of calling people cupcake. He tried to get over it but he couldn't do it. Later he watches Bob and PJ square-dancing. Mr. Hammerstone said that because of how beautiful it was, PJ could graduate high school. Later he nicknamed Teddy "T. Wrecks". The crowd of volleyball players saw Teddy accidentally break his nose. In Team Mom, Teddy and the volleyball team try to vandalize Mr. Hammerstone's house but they ended up trashing somebody else's house and they were barely seen by the police. Teddy revealed that she had to do cleaning service for the neighbors. Hammerstone lives at 306 North Birchwood Street.
He is portrayed by Sean O'Bryan.