The physical design of Jason Voorhees has gone through changes, some subtle and some radical. For "Friday the 13th", the task of coming up with Jason's appearance was the responsibility of Tom Savini, whose design for Jason was inspired by someone Savini knew as a child whose eyes and ears did not line up straight. The original design called for Jason to have hair, but Savini and his crew opted to make him bald, so he would look like a "hydrocephalic, mongoloid pinhead", with a dome-shaped head. Savini created a plaster mold of Ari Lehman's head and used that to create prosthetics for his face. Lehman personally placed mud—from the bottom of the lake—all over his body to make himself appear "really slimy."