The New Scooby-Doo Movies is the second incarnation of the Hanna-Barbera Saturday morning cartoon Scooby-Doo, Where Are You!. It premiered on September 9, 1972 and ran for two seasons on CBS as the only hour-long Scooby-Doo series. Twenty-four episodes were ultimately produced. Aside from doubling the length of each episode, The New Scooby-Doo Movies differed from its predecessor in the addition of a rotating special guest star slot; each episode featured real-life celebrities or well known fictional characters joining the Mystery, Inc. gang in solving the mystery of the week. Some episodes, in particular the episodes guest-starring the characters from The Addams Family, Batman, and Jeannie, deviated from the established Scooby-Doo format of presenting criminals masquerading as supernatural beings by introducing real ghosts, witches, monsters, and other such characters into the plots. The New Scooby-Doo Movies was the last incarnation of Scooby-Doo to feature Nicole Jaffe as the regular voice of Velma Dinkley, due to her marriage and retirement from acting.