 For the "Letterman" sketches, Gene Wilder (qv), who voiced the  heroic title character, and Zero Mostel (qv), who voiced the  villainous Spell Binder, were so excited to be working with each  other again after _Producers, The (1968)_ (qv) that they recorded  their dialogue together, a rarity in animation. The two would work  together in one film during the shows run called  _Rhinoceros (1974)_ (qv). Wilder was also devastated because of  Mostels death in 1977, soon after the show ended production.