Hearthstone has added another new hero, and this time the proceeds are going to a good cause.

Blizzard announced Khadgar, an alternate Mage portrait, is now for sale on iOS devices as part of the Apps for Earth promotion. Khadgar costs $4.99 and 100% of the proceeds will be going to the conservationist World Wildlife Fund (WWF). He's available until April 24, at which time he'll presumably go up to the more regular $9.99 cost where the other purchasable heroes have been priced.

Khadgar marks the third Mage hero available in the game, after the default Jaina and purchasable Medivh. That also makes Mage the only class to get three heroes, while five of the remaining classes in the game have no alternates at all. As a function of charity, though, it makes some sense to use Mage, since it's the hero used in the game's introduction and can catch the widest audience.

It's worth noting that currently, the PC version is incompatible with Khadgar, so if you purchase him on iOS you won't be able to play the PC version until it's patched. Blizzard has promised the update will come at approximately 12:30 PT.

Currently Hearthstone is gearing up for its next expansion, Whispers of the Old Gods. Check out our ongoing coverage with our latest round of card reviews, and look for another edition tomorrow and every Friday leading up to the launch.