I'd also add: Even if you think you are righteous and your design is not based on and doesn't bring the viewer to see similarities with DC's Catwoman, can you afford to fight them?
TD
The many Stan Lee Media suits over copyright ownership in comic book characters show that, even when a case is ultimately dismissed, the time invested in a suit and the costs involved in getting the case to the point of dismissal, can be exorbitant (although Walt Disney has the financial resources to withstand court challenges that ordinary people just do not have). Another link that, like the previous case link, is not really on point but ... Stan Lee Media, Inc. v. The Walt Disney Company (2014):
http://www.ca10.uscourts.gov/opinions/13/13-1407.pdf
Coming up with your own creative and ORIGINAL work will always be the smartest way to operate. The Court in another Neil Gaiman/Todd McFarlane copyright infringement suit from 2010 (
http://files.neilgaiman.com/crabb_decision.pdf) said this, when addressing the similarities in Gaiman"s Dark Ages knight and McFarlane's knight named Spawn:
"If defendant really wanted to differentiate the new Hellspawn, why not make him a Portugese explorer in the 16th century; an officer of the Royal Navy in the 18th century, an idealistic recruit of Simon Bolivar in the 19th century, a companion of Odysseus on his voyages, a younger brother of Emperor Nakamido in the early 18th century, a Spanish conquistador, an aristocrat in the Qing dynasty, an American Indian warrior or a member of the court of Queen Elizabeth? It seems far more than coincidence that Dark Ages (McFarland) Spawn is a knight from the 16th century as Medieval (Gaiman) Spawn."
The bottom line is that the rights in comic book characters are valuable and one is best advised not to mess with them.