This is the first "Scooby-Doo" adventure with a supernatural element (beyond the talking dog aspect). Before this, the ghosts and other fantastic elements were always revealed to be hoaxes and frauds.
Corey Anders of Jeannie (1973) was the first voice acting role of Mark Hamill. This crossover is his first time voicing a named character in the Scoobyverse. (He may have voiced unnamed bit players earlier in this series.)
Joe Besser (as Babu) is the only authentic member of The Three Stooges to appear in the Scoobyverse. Larry, Moe, and Curly-Joe in this series were voiced by mimics.
Babu, a character created by Hanna-Barbera, reappeared in Scooby's Laff-A Lympics (1977). Jeannie was also planned to appear, but complications with Columbia Pictures, who created the character for I Dream of Jeannie (1965), prohibited this.