Arthur (Disney's The Sword in the Stone) as Joffrey Baratheon-Lannister (Game of Thrones)
Joffrey was hard to cast because there simply aren't enough kids in Disney that are sadistic enough. I thought about Kuzco because he's young and egotistical but the black hair put me off. Joffrey has to be blonde. So I went with Arthur based on looks and he becomes a king as well.