Aku'mai is a level 25 elite hydra, and the final boss of Blackfathom Deeps. To complete the achievement Blackfathom Deeps, you must kill it. The ancient hydra Aku'mai, princess of the deep, has taken up residence within the Blackfathom Deeps, which once was a glorious temple dedicated to the night elves' moon-goddess Elune. A favored pet of the primordial Old Gods, Aku'mai has been a scourge to the Zoram Strand for ages. Drawn to Aku'mai's presence in the Deeps, the cult known as the Twilight's Hammer has gathered to bask in the Old Gods' evil presence by sacrificing innocents to the monstrous beast in order to gain favor with her twisted masters.