Simon Bar Sinister is the main antagonist in which American animated TV series?

"Underdog" is an American animated television series that ran from October 3, 1964, to March 4, 1967, starting on the NBC network until 1966, with the rest of the run on CBS, under the primary sponsorship of General Mills, for a run of 62 episodes. It is one of the early Saturday morning cartoons. The show continued in syndication until 1973.

"Underdog", Shoeshine Boy's heroic alter ego, appears whenever love interest Sweet Polly Purebred is being victimized by such villains as Simon Bar Sinister or Riff Raff. "Underdog" nearly always speaks in rhyming couplets as in "There's no need to fear, Underdog is here!" His voice was supplied by Wally Cox (born Wallace Maynard Cox December 6, 1924 – February 15, 1973) a former American actor and comedian, particularly associated with the early years of television in the United States.

Simon Bar Sinister is the main antagonist of the cartoon "Underdog" and the 2007 Disney live-action movie based on it where he was played by Peter Dinklage (born Peter Hayden Dinklage June 11, 1969) an American actor and producer.

Simon Bar Sinister is a soft parody to Lex Luthor as "Underdog" is a soft parody to "Superman". He sets out to take over the world, to become rich and powerful - and have the extremely common stereotypical traits of being a villain.