Mark of the Wild is a Restoration druid PvP talent, available at level 25. It applies a buff to party and raid members that reduces the damage they take from DoT and AoE spells in the Nature, Fire, Frost, and Arcane schools.
According to the non-canon RPG, Mark of the Wild is a druidic spell shared by druids, hunters, and elven rangers. By channeling the wild into a willing receptacle a caster can fill an ally with the feral grace and swiftness of the dire beasts of the Emerald Dream. Druids know two related druid-only spells called Greater Mark of the Wild, and Lesser Mark of the Wild.
Patch 9.0.1 (2020-10-13): Now requires level 25 (was 40).
Patch 8.1.0 (2018-12-11): Re-added as a Restoration druid PvP talent (was a level 62 ability for all specs). Redesigned.
Previous effect: Increases the friendly target's Strength, Agility, and Intellect by 5%, and Versatility by 3% for 1 hour. If target is in your party or raid, all party and raid members will be affected.
Patch 5.0.4 (2012-08-28): No longer increases stamina or magical resistances. Mana cost increased from 14% to 22%.
Patch 4.0.1 (2010-10-12): Now trainable at level 30 (up from level 1) and redesigned.
Mark of the Wild now increases strength, agility, intellect, and stamina by 5% (was by a flat amount based on rank), and continues to increase magical resistances, but no longer increases armor or spirit.
Duration increased to 1 hour (up from 30 minutes).