What Could Have Been: Two failed pilots were made by Total Television but were not shown on TV until Underdog went into syndication. One was "Cauliflower Cabbie" (a canine cabbie who became do-gooder The Champion), and "Gene Hattree" (a Quick Draw McGraw ripoff in that it starred a singing cowboy horse).
Only one idea for an Underdog episode was rejected by sponsors General Mills and DFS: in it, Simon Barsinister would invent a product called "Truth Paste" and replace regular toothpaste with it. Customers who bought and used the Truth Paste would become Brutally Honest and fight with each other so much that Simon would take over the city with ease. It was rejected for the idea of honesty being depicted as bad, as well as for the tampering of store products therein.
John DiMaggio voices one of the Supersheps as well as a bulldog.
Cam Clarke voices the little brown dog and Attack.
California Doubling: The fictional Capitol City is mainly Providence, RI, and a few shots have Boston's skyline; the poster has New York City, for whatever reason.
Dyeing for Your Art: Patrick Warburton bleached his dark brown hair platinum blond for the role of Cad Lackey.
Late Export for You: The film wasn't released in Japan until two years after its initial theatrical run.
