Yea, check this one ability out:
There's this evil cloud of Y'Shaarj's power that he absorbs periodically - that would be the perfect thing to cause a hideous mutation.Endless Rage: Whenever Malkorok inflicts damage that causes a player to lose health, he gains Rage proportional to the amount of health lost. When Malkorok reaches 100 Rage, he absorbs the Ancient Miasma and enters a Blood Rage.