Tantalus became one of the inhabitants of Tartarus, the deepest portion of the Underworld, reserved for the punishment of evildoers; there Odysseus saw him. The association of Tantalus with the underworld is underscored by the names of his mother Plouto (“riches”, as in gold and other mineral wealth), and grandmother, Chthonia (“earth”).
Tantalus was initially known for having been welcomed to Zeus’ table in Olympus, like Ixion. There he is said to have misbehaved and stolen ambrosia and nectar to bring it back to his people, and revealed the secrets of the gods.
Most famously, Tantalus offered up his son, Pelops, as a sacrifice. He cut Pelops up, boiled him, and served him up in a banquet for the gods. The gods became aware of the gruesome nature of the menu, so they did not touch the offering; only Demeter, distraught by the loss of her daughter, Persephone, absentmindedly ate part of the boy’s shoulder. Clotho, one of the three Fates, ordered by Zeus, brought the boy to life again (she collected the parts of the body and boiled them in a sacred cauldron), rebuilding his shoulder with one wrought of ivory made by Hephaestus and presented by Demeter. The revived Pelops grew to be an extraordinarily handsome youth.
Tantalus’s punishment for his act, now a proverbial term for temptation without satisfaction (the source of the English word tantalise), was to stand in a pool of water beneath a fruit tree with low branches. Whenever he reached for the fruit, the branches raised his intended meal from his grasp. Whenever he bent down to get a drink, the water receded before he could get any. Over his head towers a threatening stone like the one that Sisyphus is punished to roll up a hill. This fate has cursed him with eternal deprivation of nourishment.