Okay, this show is made by some of the people responsible for stuff like Batman: The Animated Series and its ilk. This obviously isn't part of that continuity, but it still has elements that might be enjoyed by more mature fans of such series. It has moments that are really pretty cool, or funny, though mostly it is very kiddie level stuff, just not in a bad (cringe-inducing) way. Usually. And most importantly, if little kids get introduced to the genre by stuff like this, a love of comix might be instilled in them from an early age, and later on they might start collecting comix, thus revitalizing the industry. That's my hope, anyway.
Now then, what's the show about? Well, when Kal-El (who would become Superman) was still a young boy on Krypton, he had a puppy. (I know, he should have left when he was a baby. Just go with it.) His dad put the puppy in a rocket for some kinda tests or whatever, and when there was a malfunction, the ship put him into cryosleep. Years later he awoke, full-grown, and landed on Earth. There he was befriended by a boy named Kevin Whitney, who named him Krypto. (By then, Superman was a well-known superhero on Earth, and oddly enough, an average kid like Kevin knows things like that he's from Krpyton and is affected by Kryptonite, and stuff.) Krypto discovers that he has super powers, so he becomes a superhero called Superdog (though Kevin and Superman are the only people who know Krypto is Superdog; unless you count Kevin's toddler sister Melanie).
Superman (who we only really see in the first episode, briefly) lets Krypto stay with Kevin. Also Krypto gets a friend, a cat named Streaky who belongs to Kevin's neighbor, Andrea. An accident in an early episode copied Superdog's powers onto Streaky, who becomes Superdog's sidekick, Supercat. There are other superhero animals that show up sometimes, including the Dog Star Patrol, and Batman's dog, Ace the Bathound. Lex Luthor also makes the occasional appearance (though not as a villain), as does his pet iguana, Ignatius (who is more of a self-centered nuisance than a true villain, though he does make trouble). There are several recurring (animal) villains, though the main ones are Mekanikat, and his henchman, Snooky Wookums. And that's about all I can think to say for now. I suppose there must have been episodes that I never got to see, but... it really was a cute, fun little show.