Quoted from Wikipedia
"
Taliesin began life as Gwion Bach, a servant to the enchantress Ceridwen. Ceridwen had a beautiful daughter and an ugly son named Morfran (also called Avagddu), whose appearance no magic could cure.
Ceridwen sought to give him the gift of wisdom as compensation and cooked a potion granting inspiration (Awen), which had to be constantly stirred and cooked for a year and a day.
A blind man named Morda tended the fire beneath the cauldron, while Gwion Bach stirred. The first three drops of liquid from this cauldron would give wisdom; the rest was a fatal poison.
Three hot drops spilled onto Gwion's thumb as he stirred, and he instinctively put his thumb in his mouth, instantly gaining wisdom and knowledge. The first thought that occurred to him was that Ceridwen would kill him, so he ran away.
All too soon he heard her fury and the sound of her pursuit. He turned himself into a hare on the land and she became a greyhound. He turned himself into a fish and jumped into a river: she then turned into an otter. He turned into a bird in the air, and in response she became a hawk.
Exhausted, he turned into a single grain of corn and she became a hen and ate him. She became pregnant. She resolved to kill the child, knowing it was Gwion, but when he was born he was so beautiful that she couldn't, so she threw him in the ocean in a leather bag.
The baby was found by Elffin, the son of Gwyddno Garanhir, 'Lord of Ceredigion', while fishing for salmon. Surprised at the whiteness of the boy's brow, he exclaimed "dyma Dal Iesin", meaning "this is a radiant brow." Taliesin, thus named, began to recite beautiful poetry, saying:
Fair Elffin, cease your lament!
....Though I am weak and small,
On the wave crest of the surging sea,
I shall be better for you
Than three hundred shares of salmon.
Elffin of noble generosity,
Do not sorrow at your catch.
Though I am weak on the floor of my basket,
There are wonders on my tongue....''
Amazed, Elffin asked how a baby could talk. Again Taliesin replied with poetry:
"Floating like a boat in its waters,
I was thrown into a dark bag,
and on an endless sea, I was set adrift.
Just as I was suffocating, I had a happy omen,
and the master of the Heavens brought me to liberty."
en.wikipedia.org/wiki/Taliesin