The infancy of Achilles

Apollodorus The Library
The early life of Achilles:

When Thetis gave birth to a child by Peleus, she wanted to make it immortal, and in secret from Peleus, she used to bury it in the fire by night to destroy the mortal element in its nature that came from its father, and rubbed it by day with ambrosia.

But Peleus kept a watch on her, and shouted out when he saw the child squirming in the fire; and Thetis, frustrated in her purpose, abandoned her infant son and went back to the Nereids.

Peleus delivered the child the child to Chiron, who took him in, and fed him on the entrails of lions and wild boars and the marrow of bears, and named him Achilles [lipless] - his former name was Ligyron - because he had not applied his lips to a breast.