Bašmu

thumb|The Weather god, armed with lightning, fighting a Bašmu dragon, on a Neo-Assyrian cylinder seal (9th/8th Century BC)

Bašmu or Bashmu (; cuneiform: MUŠ.ŠÀ.TÙR or MUŠ.ŠÀ.TUR,  "Venomous Snake") was an ancient Mesopotamian mythological creature, a horned snake with two forelegs and wings. It was also the Akkadian name of the Babylonian constellation (MUL.DINGIR.MUŠ) equivalent to the Greek Hydra. The Sumerian terms ušum (portrayed with feet, see Ninurta's Dragon) and muš-šà-tùr ("birth goddess snake", portrayed without feet) may represent differing iconographic types or different demons. It is first attested by a 22nd-century BC cylinder inscription at Gudea.