* TheOtherDarrin: A variation: Gary Owens, the voice of WesternAnimation/SpaceGhost in the original 1960s cartoon, is used by the current Space Ghost's former mentor, Warren, as a replicant so he could have Space Ghost on his own show. Gary is rendered as an image of Space Ghost over a boiling cauldron that occasionally blinks into his real face. The real Space Ghost, feeling that Warren violated their trust as mentor and student, confronts him and Gary to reclaim his identity.
** In "Spanish Translation", Brak was voiced by C. Martin Croker. In all other appearances, he was voiced by Andy Merrill.
** In "Woody Allen's Fall Project", Space Ghost was played by Andy Merrill, Zorak was played by Dave Willis, and Moltar was played by Gus Jordan.
* TalkingToHimself: C. Martin Croker voices Zorak and Moltar (though his voice was pitched down electronically for Moltar's lines).
* WhatCouldHaveBeen: As it was created as a BackdoorPilot (but broadcast after the series' launch), the episode "Baffler Meal" features outdated, preliminary versions of the WesternAnimation/AquaTeenHungerForce just 'cause.
** It also shows us a new future of rock 'n' roll dominated by Colonial-era musicians, who perform a bizarre cover of "[[Music/LedZeppelin Black Dog]]" with fast-food-related lyrics.
** While it was in pre-production, [[FantasyIsland Hervé]] [[Film/TheManWithTheGoldenGun Villechaize]] was in negotiations to co-star as a sidekick of Space Ghost. Sadly, he killed himself before anything happened.