Aired: Saturday December 31, 1988
Writer: Francis Moss
Synopsis: When Donald loses some scripts, Slimer flies to his school to give them back to him ... but not after having a few encounters with Mrs. Stone, the school's tough guard.
- April Hong [Catherine]
- Katie Leigh [Jason, Teacher]
- Danny McMurphy [Donald]
- Cree Summer [Stoneface]
- The script for this episode can be found on the Slimer! Scripts page.
- Title Reference: The "class clown" is the student in a class who likes to joke around and pull pranks on the teacher.
- The voice actors were recorded on July 27, 1988.
- The Junior Ghostbusters are named Catherine, Jason, and Donald, and they attend Reitman Junior High School. Ivan Reitman's (the director of "Ghostbusters") children are named Catherine and Jason.
- In The Real Ghostbusters, Lennard Camarillo voiced Donald, the Junior Ghostbuster. In Slimer!, Danny McMurphy took over the role.