Time and again, there have been characters created as satires of Superman who have achieved iconic status of their own. Mighty Mouse was one, and was well established on Saturday mornings by the time Total Television introduced Underdog in 1964.
Underdog spent 9 seasons between CBS & NBC, but by the time I became acquainted with him, the series was out of production and in perpetual rerun. Here's the first part of the episode, "Go Snow", which would be appropriate for winter:
Actor-comedian Wally Cox (ex-Mr. Peepers, later of Hollywood Squares) voiced the title hero and his meek alter ego, the generically named Shoeshine Boy. The one glaring difference between the two personas was Underdog always spoke in rhyme. I'm actually more surprised no one's tried to create a rap video based on this show!
As for that live-action/CGI movie version that Disney put out a few years back with Jason Lee (ex-My Name Is Earl) voicing the title character? A poser, nothing more! Purists should disavow any knowledge of its existence!