By the time he was a teenager, he had built almost 90 puppets, which he based upon commercials, popular music, and his friends. While still in high school, Clash performed at venues throughout Baltimore, including schools, churches, fundraisers, and community events. While appearing at a neighborhood festival, Clash was discovered by Baltimore television personality Stu Kerr, who became Clash's first mentor and hired him to perform in the children's show Caboose at Channel 2. Clash also built puppets for the Romper Room franchise. When he was 17, he contacted and met Puppeteer Kermit Love, who became Clash's mentor, after seeing Love featured in an episode of the documentary Call It Macaroni. In 1979, on Love's recommendation, Clash appeared as Cookie Monster in the Sesame Street float during the Macy's Thanksgiving Day Parade, and met Jim Henson, who later became his boss, mentor, and good friend.