Peter Segal Director Eddie Murphy Professor Sherman Klump, Clesius "Papa" Klump, Young Clesius Klump, Mama Klump, Ernie Klump, Grandma Klump, Buddy Love, Lance Perkins Actor, Executive Producer Janet Jackson Professor Denise Gaines Actor, Original Music Larry Miller Dean Richmond Actor John Ales Jason Actor Richard Gant Mr. Gaines Actor Anna Maria Horsford Mrs. Gaines Actor Melinda McGraw Leanne Guilford Actor Jamal Mixon Ernie Klump Jr. Actor Gabriel Williams Isaac Actor Steve Oedekerk Writer Barry W. Blaustein Writer, Screenwriter David Sheffield Writer, Screenwriter Paul Weitz Screenwriter Chris Weitz Screenwriter James D. Brubaker Executive Producer Michael Ewing Co-Producer Brian Grazer Producer Arlene Kehela Associate Producer Karen Kehela Sherwood Executive Producer Jerry Lewis Executive Producer Tom Shadyac Executive Producer James Whitaker Co-Producer David Newman Original Music Dean Semler Cinematographer William Kerr Film Editing Pamela Basker Casting Joanne Koehler Casting William A. Elliott Production Design Greg Papalia Art Director John Anderson Set Decoration Sharen Davis Costume Design Rick Baker Special Makeup Effects Artist Kerry Mendenhall Hair Stylist