Udder Cowlamity is an Event in Diablo III, only available in March. It only occurs in Adventure Mode. To start it, one needs to get into Ruins of Sescheron, enter the Elder Sanctum, find Immortal Throne and approach the throne itself. On the way, huge braziers will light as the Nephalem steps close, and the chasm beneath the throne will ignite and burn brightly. As Kanai is approached, he will awaken, his spirit getting out of the body, and open a red portal, entering it shortly and inviting the hero to join him without saying a word.