The third season episode "The Littlest Yarbo" replaces the show's usual closing credits theme with "Maybe Tomorrow", the theme song from the 1980s TV series "The Littlest Hobo."
During the Christmas-themed 13th episode of the 3rd season, "Merry Gasmas", the theme-music during the opening credits features Christmas bells playing beneath the normal instrumentation.
During the closing credits of "Rock On", instead of the usual closing theme song, Thunderface (Brent, Hank, Wanda, and Karen) performs Fast Exit's song "Capital Cash", as they did in the episode.