A Witcher.

Your parents gifted you to a witcher. And the famous Butcher of Blaviken no less.

The moment your parents decided to offer their unwanted first born, they must have been desperate. Or they never loved you. Either one

"In the cart" he grunts, he agreed to take you rather reluctantly "don't make me ask again."

You don't blame him. You wouldn't want yourself either. You were small and sickly. you were essentially a Runt. Witchers have no use for Runts. You are just extra baggage.