Leave It to Beaver · S3, E12
Beaver the Magician
Beaver plays a trick on Benjie where he convinces Benjie that he can turn himself into a rock. Benjie really believes this trick, and won't believe that Beaver is okay unless he can make sure that Beaver is turned back into a boy. The problem is that nobody can find Beaver, because he has gone to his Aunt Martha's house.
