Tammuz, originally known as Dumuzid, and often simply called Damu ("son"), was the Mesopotamian god of shepherds (and the goods provided by them, especially milk) and vegetation. He was also often regarded as the consort of Inanna (as Dumuzid, in Sumer)/Ishtar (in Babylonia and Assyria, as Tammuz). In Sumerian king lists, he was also mentioned as an ancient human monarch who reigned before the deluge caused by Enlil. Yet another tradition, recorded for example in the myth of Adapa, presents him as one of the two doorkeepers of the sky god Anu.
In the myth Dumuzid and Enkimdu, he competes with Enkimdu, an obscure god associated with farming and irrigation, to win Inanna's hand in marriage. In Inanna's descent to the netherworld, he's condemned to take Inanna's place in the underworld after she learns that he didn't mourn her temporary death. Eventually his sister Geshtinana, accompanied by their mother and by Inanna (after a change of heart), offers a deal to Ereshkigal to recover him: each year Tammuz will be imprisoned for 6 months, but for the remaining 6 Geshtinana will take his place. This myth was supposed to explain the passage of seasons.
In Mesopotamian art, Tammuz was depicted as a young man.
In the Dictionnaire Infernal, Tammuz is a demonic inventor of artillery and hell's ambassador to Spain.
"Origin: Spain. A monstrous scorpion of Spain. He is also the Babylonian god of plants. He is Ishtar's brother and husband, whose name means 'Loyal son.' He is also known as a god of irrigation, and he is constantly dying and being reborn."