Batman: Arkham City has no shortage of fashionable looks for our favorite flying mammal-based superhero. But as we often find in bonuses like these, you'll have to choose your store wisely to get the ones you want. Among the bevy of incoming skins is one based on the highly regarded 90s animated series, but you'll need a GameStop PowerUp membership to parade around Arkham looking like a cartoon.

GameStop (via Joystiq) reveals that the skin is a PowerUp Rewards exclusive. The rewards program gives points for purchases that can be used on goodies like this one. If you've bought from a GameStop in the last year, chances are you've at least been offered a PowerUp card. Collectors can only hope that, eventually, Rocksteady gathers all the disparate skins together for a DLC pack.

Now for the worse news. If you're a PC gamer, you'll have to wait an extra month to punch some Arkham City goons. Warner Bros Interactive Entertainment announced today that the PC version will come sometime in November, following the mid-October release on consoles.