And speaking as we were yesterday of odd failed TV pilots, faithful commenter The Phantom Creep posited the possible existence of a followup series to TVs Adventures of Superman involving canines. Not the teeth, obviously.
Well, it turns out he didn't imagine it. Behold -- The Adventures of Superpup!
I must admit that I'd completely forgotten about the existence of this, although upon reflection I know I read about it in Gary Grossman's Superman: Serial to Cereal, the definitive study of the TV show's history, back in the '70s. In any case, Superpup was shot in 1958 by the original series' producer Whit Ellsworth, who apparently thought it was a good idea at the time. The pilot first surfaced, officially, on home video in the 2006 Superman Ultimate Collector's Edition, a 14-DVD set that also includes all the feature films, the great 1940s Max Fleischer Superman cartoons, and lots of other goodies.
You can watch the rest of Superpup over here; it switches to black-and-white because the complete color print has not, alas, survived.
I should add that given just about everybody's unhappiness with Superman Returns, Bryan Singer's disappointing attempt to reinvigorate the movie franchise, perhaps Warner Bros. should consider the above example as a possible direction for future big screen Superman projects. I understand the Taco Bell Chihuahua is between jobs at the moment.