The Greek personification of Death, elder brother of Hypnos (Sleep) and son of Nyx (Night) - according to Hesiod they had no father:
"Night gave birth to hideous Moros and black Ker
and then to Death and Sleep and to the brood of
Thanatos' primary responsibility was to collect the spirit of a dying person after the Fates snipped their thread of life. Upon attempting to claim Sisyphus' soul Thanatos was imprisoned - his power lost until Ares freed him. For this period Death was suspended - mortals lived as immortals.
Neil Gaiman based his character Death (from the Sandman series) on Thanatos and a fair portion of the 'Preludes and Nocturnes' plot on Thanatos imprisonment and the subsequent upset of order. Death's younger brother (Dream, based on Hypnos aka Morpheus, Murphy) is imprisoned, causing chaotic effects among man and animal sleeping patterns. Millions don't wake up, millions more can't truly sleep. Madness is the popular result. Bring me a dream ... indeed.
Homer gave the brothers further responsibilities in his Iliad - in the following passage Zeus implores Apollo to assign Thanatos and Hypnos the removal of Sarpedon's body from the battle field:
Come, dear Phoebus,
wipe away the blood mantling Sarpedon;
take him up, out of the play of spears,
a long way off, and wash him in the river,
anoint him with ambrosia, put ambrosial
clothing on him. Then have him conveyed
by those escorting spirits quick as wind,
sweet Sleep and Death, who are twin brothers. These
will set him down in the rich broad land of Lykia,
and there his kin and friends may bury him
with tomb and stone, the trophies of the dead."
One of few stories involving Thanatos is a small part in Euripides play 'Alcestis' - the story of a Greek heroine. In order for the hero Herakles to rescue Alcestis, he had first to wrestle "the dark-robed lord of the dead". Thanatos, dressed cool or not, is overcome by Hercules and Alcestis splits with the hero.
Thanatos appeared in few other plays or myths as his position in Greek history was mostly assimilated by the greater god Hades. Thanatos' symbols are an inversed torch, a wreath, a butterfly or a young man armed with a sword.
Greek And Roman Mythology