Wild card is a Dungeoneering reward perk. For 20,000 Dungeoneering tokens, it unlocks the ability to gain a random free card upon entering a Sinkhole. Despite the icon in the shop displaying a Beguiling Smoke Devil card, the card received at the beginning of each sinkhole is random. This perk was released on 27 May 2014.
It is not possible to buy this unlock a second time, doing so will yield the message "You have already unlocked this perk."
Unlocking this perk is a requirement for the trimmed completionist cape.