What is "humbaba"

In Ancient Mesopotamian religion, Humbaba ( Assyrian spelling), also spelled Huwawa ( Sumerian spelling) and surnamed the Terrible, was a monstrous giant of immemorial age raised by Utu, the Sun. Humbaba was the guardian of the Cedar Forest, where the gods lived, by the will of the god Enlil, who "assigned [Humbaba] as a terror to human beings."