Sumerian calls him Imdugud; Akkadian calls him Anzu; and both mean a bird the size of a storm — a lion-headed eagle whose scream is described as a gale and whose wings, spread, are the standard emblem of the thundercloud in early Mesopotamian art. The most spectacular surviving image of him is a copper-alloy relief from the temple at Tell al-Ubaid, now in the British Museum, in which he grips two stags by their tails, his wings filling the width of a lintel.
That image was made for a temple of Ninhursag, and the same creature was the heraldic emblem of Ningirsu at Lagash — the god who, under his other name Ninurta, later kills him. A god's badge became a god's enemy somewhere between the third and second millennia, and nobody has fully explained the reversal.
The theft
The Akkadian Epic of Anzu, in three tablets, opens with him being given a job. He is brought from the mountains into Enlil's service and stationed at the door of the inner chamber, where he watches the god remove his crown and lay aside the Tablet of Destinies to bathe. Familiarity does the rest: he sees the emblems of supreme office treated as clothing, and he takes the tablet and flies back to the mountain.
What follows is not a manhunt but a constitutional crisis. Enlil goes silent, the divine order stops functioning, and the assembly discovers a problem it had not anticipated — because whoever holds the tablet issues decrees, and Anzu can therefore command his attackers. Anu calls for a champion and is refused three times, by Adad, by Gerra the fire god and by Shara, each of whom gives the same reason: how can anyone fight a creature whose word is now law? It is the only passage in this literature where the gods are stopped by a point of procedure.
Killed by an argument about arrows
Ninurta is put forward by the mother goddess and goes. His first assault fails exactly as predicted. He looses an arrow and Anzu shouts at it — reed, go back to your canebrake; feathers, go back to the birds; sinew, go back to the animal's shoulder — and the arrow disassembles into its raw materials in mid-air and falls. A weapon is only a set of parts held together by a command, and the holder of the tablet has authority over commands.
The counter-strategy comes from Enki, relayed to Ninurta by the talking mace Sharur: shoot so that the arrow strikes Anzu's own pinion feathers, so that when the bird orders feathers back to the birds his own wing is included in the recall. The incantation is turned against the incanter, his flight fails, and the tablet is recovered. Winning by finding a flaw in the wording of a spell is a very Mesopotamian kind of heroism, and the same logic — obey the letter, defeat the intent — runs through the flood story too.
The bird before the villain
Older Sumerian material treats him quite differently, and the difference is worth holding onto.
In Lugalbanda and the Anzud Bird, a stranded hero finds the great bird's nest while the parents are away, feeds and adorns the chick, and paints its eyes with kohl. When Anzud returns and finds his young decorated and content, he offers Lugalbanda whatever he wants, and Lugalbanda asks for speed — receiving the ability to run faster than anything alive, which is what gets him home. There is no theft, no crime and no punishment. The Anzud here is a formidable but reciprocating power, dangerous to offend and generous when honoured.
He also nests in the huluppu tree in the Sumerian prologue that Gilgamesh intrudes on, alongside a serpent at the root and a female demon in the trunk — one nest, three unwanted tenants in a tree Inanna wanted for furniture.
Why a lion-headed eagle at all
The composite is doing meteorological work. An eagle supplies flight, height and a raptor's descent; a lion supplies the roar. Mesopotamian texts describe the thunderstorm arriving off the plain as something that comes down out of the sky and takes livestock, and the hybrid encodes both halves of the experience. Compare the way other traditions build their storm birds — the divine birds hub sets the parallels out, and the wider habit of building a creature from parts is followed on the hybrid beasts page.
Questions about the storm bird
Is he the ancestor of the roc or the thunderbird?
Very probably not directly, and the resemblance is the point at which comparison should slow down. Enormous predatory birds are independently plausible in any culture that watches raptors and storms, and the specific chains of transmission that would be needed — from Sumerian Imdugud to the Arabic rukh of the Sindbad cycle, or to North American thunderbird traditions — do not exist. What can be said is narrower and better evidenced: the lion-eagle composite persisted in Mesopotamian and neighbouring art for two millennia, and the griffin of the eastern Mediterranean belongs to a related family of eagle-and-feline hybrids that were genuinely in contact.
Did the Sumerians have a version of the theft story?
Fragments suggest something like it. Ningirsu's trophy list at Nippur includes the Anzu, and there are Sumerian allusions to the bird being defeated, but no complete Sumerian narrative of the tablet's theft has been recovered. The full plot as we have it is the Akkadian composition, which is itself known from Old Babylonian and Standard Babylonian recensions that differ in detail — one of them naming Ningirsu rather than Ninurta as the victor. This is normal for the corpus: the surviving text is one version of a story that was told in several.
What happened to him after he was killed?
He was recycled as decoration and as protection. Anzu appears bound and defeated on Assyrian reliefs, hung on Ninurta's chariot in the triumph poem, and reduced in later art to an ornamental motif. There is also a sequence of first-millennium ritual texts in which images of defeated monsters are set up as guardians — a defeated enemy is a proven quantity and can be posted at a door, the same reasoning that put Pazuzu's face on a household amulet. Nothing in Mesopotamia is wasted, least of all a monster.