Yeah, I thought he was from the Bizzaro Universe too. Jerry Seinfeld even explained him in one episode of the tv show lol.

eh, its based off the Superman animated series then.

Luther managed to get a sample of blood, and used it to create clones of superman he hoped to use for well, Luthery things, but the clones DNA breaks down rather quickly, and what we got was well, Bizarro. Superman actually helped Bizzaro find a safe place for him to "save" things, and all was well, until the pesky leprechaun-like being from the 5th dimension brought him back to Metropolis. I hope they don't try to make him some brain-dead evil guy though, he's one of my favorite villains because he's a unique guy.

(all if my memory serves me right, been a while since I've seen the animated show)