New purchases of Batman: Arkham City will include a one-use code enabling access to playable Catwoman content.
Warner Bros. confirmed the online pass system with Eurogamer, explaining that while Catwoman will appear in-game regardless, only those with the DLC will be able to play as the notorious quasi-villain.
The extra content is completely optional, and will available for £7.99 or 800 MS Points for those who pick up a used copy. Unlocking the Catwoman content grants four story scenes and a challenge map.
Catwoman joins Robin and Nightwing among many other offerings available as premium DLC, or as retailer exclusive bonuses.
Batman: Arkham City releases next week on PlayStation 3 and Xbox 360, with a PC version delayed until November and Wii U version expected.