Gallu

In Sumerian and Akkadian (Babylonian and Assyrian) mythology, Gallu (also called gallu demon or galla (Akkadian: gallû)) was a wild spirit or underworld demon that, under the shape of a bull, went through the cities, especially by night. This demon can frequently alter its form and haunts dark locales. It was believed that Gallu could attack anyone who was at sight. It is not clear if these peoples believed in only one Gallu or in an undetermined number of them. Gallu demons hauled unfortunate victims off to the underworld. The gallas are one of seven types of demons mentioned in incantations. It is said that there are seven gallas as well. Inana is accompanied by gallas as she is returning from the underworld. Dumuzi was seized by gallas and brought him to the underworld. Sumerian poems describe tell of the sheep he left behind. The minor god Ig-alima is called 'the great galla of Girsu'.
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[Mesopotamian] The Akkadian demons of the underworld. They are responsible for the abduction of the vegetation-god Damuzi (Tammuz) to the realm of death.

Gallu In Chaldean theology, a class of spirits beneath the angels of earth {SD 2:248}.