It's a Mystery, Charlie Brown
- Rok: 1974
- Krajina: United States of America
- Žáner: Animovaný, Komédia
- Štúdio: Lee Mendelson Film Productions, Bill Melendez Productions
- Kľúčové slovo: detective, dog, beagle
- Riaditeľ: Phil Roman
- Obsadenie: Todd Barbee, Melanie Kohn, Stephen Shea, Donna Le Tourneau, Jimmy Ahrens, Lynn Mortensen