Who's This? The man with nine lives.
The facts: Cat-Man was a silly crossbreed between Batman and Catwoman created by Bill Finger and Jim Mooney for Detective Comics #311 (January 1963) and initially, he's just like Catwoman, committing cat-inspired crimes. In his next appearance, he had a magical costume that supposedly gave him nine lives. He appeared seldom and by the 90s, was a joke. In Green Arrow #16, toy-breaker Brad Meltzer suggests he was eaten by Monsieur Mallah (gorillas eating cats? that's not even good irony). The character is finally rehabilitated in 2005 by toy fixer Gail Simone who gives him back his mojo, a proper personality, and leadership of her Secret Six. There he thrives as the world's first bisexual antihero and one of the best characters in the series (noted for having a LOT of great characters).
How you could have heard of him: The New52 had a short-lived Secret Six series that also included Catman (he loses the hyphen after Crisis), and though different versions of the character exist in non-comics media, his appearance in The Brave and the Bold cartoon is a proper one.
Example story: Detective Comics #509 (December 1981) "Nine Lives Has the Cat..." by Gerry Conway, Don Newton and Dan Adkins
I think series like Suicide Squad and, in this case, Secret Six serve as proof that there really aren't any bad characters, just creators with lack of vision for such characters. Cat-Man was never more than a gimmick, and then, by lack of imagination, a joke until Gail Simone saved him from the jaws of infamy. So don't give up on anyone, you never know when their time will come!
Who's Next? Batman's wife.