Ušumgallu, inscribed: ú-šum-gal-lu, from Sumerian: ušum.gal, “dragon” and meaning "Great Dragon" or “prime venomous snake” according to Wiggermann, somewhat speculatively identified with the four-legged, winged dragon (Ušum) of the late 3rd millennium, was a lion-dragon demon whose name Winter translates as “predator.” It was one of three horned snakes in Akkadian mythology, with Bašmu and Mušmaḫḫū.
Tiāmat is said to have “clothed the raging lion-dragons with fearsomeness” in the Epic of Creation, Enûma Eliš. The god Nabû was described as “he who tramples the lion-dragon” in the hymn to Nabû. The late neo-Assyrian text “Myth of the Seven Sages" recalls: “The fourth (of the seven apkallu’s, “sages,” is) Lu-Nanna, (only) two-thirds Apkallu, who drove the ušumgallu-dragon from É-ninkarnunna, the temple of Ištar of Šulgi.”
Aššur-nāṣir-apli II placed golden icons of ušumgallu at the pedestal of Ninurta. Its name became a royal and divine epithet, for example: ušumgal kališ parakkī, “unrivaled ruler of all the sanctuaries.” Marduk is called “the ušumgallu-dragon of the great heavens.”