Mam'toth Crater

Mam'toth Crater is the result of the mammoth loa, Mam'toth, destroying himself rather than allowing his ice troll followers to gain his power. All that's left is a crater crawling with blue ooze, which is what remains of his blood.

Following the war against the Jailer, the brothers Bronzebeard visited the Altar of Mam'toth and reported that the crater was still crawling with his blood.