Scooby-Dum is a an animated cartoon dog created by Hanna-Barbera Productions, who appeared in four episodes of the ABC Saturday morning cartoon series Scooby-Doo between 1976 and 1978.
Scooby-Dum, a grey Great Dane with spots, buck teeth, and a generally dim-witted demeanor, is Scooby-Doo's cousin. Dum lives with Ma and Pa Skillet in the Okefenokee swamp of southern Georgia. Whenever Doo and Dum greet each other, they do a special handshake involving two high fives. The character of Scooby-Dum was partially derived from that of Mortimer Snerd, one of comedian/ventriloquist Edgar Bergen's popular radio and puppet characters.
Dum made his first appearance during the Scooby-Doo half of The Scooby-Doo/Dynomutt Hour on September 18 1976, in an episode entitled "The Gruesome Game Of The Gator Ghoul". In this episode, Scoobies Doo and Dum, and the Mystery Inc. gang of Fred, Daphne, Velma, and Shaggy, help solve a mystery involving an alligator monster who is trying to put an end to the Skillets' production of their popular "Finokey Fizz" soft drink.
Dum appeared in one more 1976 episode of Scooby-Doo, "The Headless Horseman of Halloween", which first aired on November 20 1976. He made two appearances in 1977, when The Scooby-Doo/Dynomutt Hour was expanded into Scooby's All-Star Laff-a-Lympics: "Vampires, Bats, and Scaredy Cats" on September 17 1977, and "The Chiller Diller Movie Theater" (also featuring Doo and Dum's female cousin Scooby-Dee) on October 1 1977. Dum also appears in all of the Laff-a-Lympics segments of Scooby's All-Star Laff-A-Lympics as a member of the "Scooby Doobies" team.