When the second season crew took over, they brought in Don Messick to play Dr. Benton Quest. But Messick's poor health condition caused difficulty for him while playing Dr. Quest in the first few episodes of the second season, so they had to replace him with John de Lancie, who redubbed the episodes, in which Messick had played. But one line of dialogue by Messick wasn't re-dubbed, his "and not a moment too soon" can be heard in season two, episode two, "Rock of Rages".

Featured in Animation Lookback: Hanna-Barbera Part 2 (2010)