Today is Scooby Doo day!

• The cartoon debuted on CBS September 13, 1969, and new episodes still air in syndication, making it the longest-running animated series ever.
• A CBS exec named the dog after hearing Frank Sinatra's nonsense line "Scooby-dooby-doo" in his hit song "Strangers in the Night."
• Scooby's human co-stars Fred, Daphne, Velma and Shaggy were inspired by the "I Love A Mystery" radio show and the sitcom "The Many Loves of Dobie Gillis."
• The show was originally titled "Mysteries Five And Who's Scared?" before bigwigs settled on "Scooby-Doo, Where Are You?"
• The dog breed was chosen by a show artist, who was friends with the owner of an award-winning Great Dane.
• Scott Innes provided Scooby's voice for the movie. On TV, the talking Great Dane was voiced by Don Messick, who also provided the vocals for Bamm-Bamm of "The Flintstones" and Yogi Bear's buddy Boo-Boo.
• A young Dave Coulier was hired to supply various voices for the TV cartoon. Later, he starred with the Olsen twins on ABC's "Full House."
• Strict vegetarian Casey Kasem voices Shaggy on the TV and insists every snack his cartoon counterpart eats is completely meatless.
• Brainy Velma has never piloted the four-wheel-drive Mystery Machine van. At 15, she's not old enough to have a driver's license.
• In 1997, NASA scientists honored the series by dubbing a rock floating around Mars "Scooby-Doo."