(You are Zuko's brother - I want you as a baby so he'll do anything to get it. You have a curse so your body has layers of skin)

Zuko entered your room - he had a bottle of warm milk with a crushed tablet which regresses the development of your brain in his hand and a scalpel in the other hand. New layers of skin grew so he had to peel them off so you had a body of a child again