From the First Branch of Y Mabinogi
(Rhiannon's baby has been snatched away,
then the action switches to Teyrnon in Gwent):
Teyrnon had the mare brought into the house, then he armed himself for his vigil. As darkness fell, the mare gives birth to a large, good-looking foal, standing up on its feet. Teyrnon gets up to admire the sturdiness of the foal. As he does so, he hears a mighty commotion - and, following this commotion an enormous claw appears through the window, seizing the colt by its mane. Then what Teyrnon does is draw his sword and cut the arm from the elbow down - so that most of the arm, together with the colt, is inside the house.
Then he hears the sound of a commotion and a scream together. He opens the door and follows the commotion. He can't see where it is coming from as the night is so dark. But he keeps going towards it. Then he remembers that the door is open and goes back. By the door what does he see but a small child in swaddling clothes, wrapped in a sheet of brocaded silk. He picks up the boy, and observes that he is strong for his age.