In Welsh mythology, Ceridwen was a magician, mother of Taliesin, Morfran, and a beautiful daughter.

Morfran (also called Avagddu) was hideously ugly, so she sought to make him wise. Ceridwen had a magical cauldron that could make a potion granting wisdom. The mixture had to be cooked for a year and a day. Morda, a blind man, tended the fire beneath the cauldron, while Gwion, a young boy, stirred the concoction.

The first three drops of liquid from this cauldron gave wisdom; the rest was a fatal poison. Three hot drops spilled onto Gwion's hand as he stirred, burning him. He instinctively put his hand in his mouth, and instantly gained great wisdom and knowledge.

Ceridwen chased Gwion. He turned himself into a rabbit. She became a dog. He became a fish and jumped into a river. She turned into an otter. He turned into a bird; she became a hawk. Finally, he turned into a single grain of corn. She then became a hen and ate him.

When Ceridwen became pregnant, she knew it was Gwion and resolved to kill the child when he was born. However, when he was born, he was so beautiful that she couldn't do it. She threw him in the ocean instead. The child did not die, but swam away and became the legendary bard, Taliesin.