Children are natural practical jokesters, but this time it's the whippersnappers who get pranked. "The Substitute" is a hidden camera show that features celebrities who go under cover as professionals in various fields, surprising unsuspecting kids in schools, camps and other locations. Transformed by a team of special effects artists, the celebrities hide their true identities as they attempt to fool unsuspecting youngsters. During the reveal of a celebrity, a $25,000 donation is made to the organization.