While Demeter searched for Persephone in the guise of an old woman called Doso, Celeus asked her to nurse Demophon, his son by Metaneira. As a gift for hospitality she planned to make the child a god: anointing him with ambrosia, breathing gently upon him at her bosom, and by night concealing him in the force of the hearth-fire "as if he were a smoldering log," without the parents' knowledge.

The Homeric Hymn says he grew like a divine being, neither eating grain nor suckling. His parents marveled that to look at him was like looking at the gods — until Metaneira saw him in the flames and cried out.

Interrupted, Demeter declared there was no longer a way for him to avoid death and doom, yet promised a tīmē that is unwilting for all time because he had sat on her knees and slept in her arms. Each year, at the right season, the sons of the Eleusinians would wage a terrible battle among themselves in his honour — the Ballêtus, a ritual mock-battle understood as the kernel of the Eleusinian Games and a compensation for the baby cult-hero's death.

Some later theories claimed the bungled immortalization caused his death; in the hymn the emphasis falls on lost immortality and lasting cult honour rather than immediate destruction. Forestalled in deifying Demophon, Demeter taught his elder brother Triptolemus (in the prose genealogies) the art of agriculture and sent him over the earth in a dragon-drawn chariot.

Eleusinian Demophon, the hearth-child of the Homeric Hymn, is a separate figure from Demophon son of Theseus and Phaedra, the Athenian prince who appears in the Returns and Attic king-lists. The shared name reflects the density of Demophon/Demophoon formations in Greek myth, not a single biography.