Jack Mercer was Popeye's voice for most of the cartoons, and Mae Questel was
Olive Oyl's. But when Mercer went into the army in the '40s, Questel did BOTH
voices! Much of the dialogue between Popeye and Olive was ad-libbed in the
Fleischer cartoons.

Felix the Cat's was the first image ever to appear on TV. In 1928, when the first
experimental TV broadcast occurred, the subject was a Felix doll. The origin of
Felix's name: it came from the word "felicity," which means "great happiness."

(Source: TV trivia expert John Javna)