At that time he had an accident that gave him a concussion. As a result, he was able to visualize better, thus increasing his production and animation. He was the head animator and go-to guy in the late 1930s at the studio, which overwhelmed him. Eventually he worked exclusively with Bob Clampett. [1] He was offered a directorial position by Leon Schlesinger in 1937, but declined, allowing the position to go to animator Chuck Jones.[1] He accepted his own directorial position in 1944, when Frank Tashlin left Warner Bros. to direct live-action films.[2]