Killua has spiky silver hair, very pale skin, and blue eyes. Initially, Killua is introduced as a character who appears similar to Gon: cheeky, cheerful, and full of mischievous ideas. However, Killua can be quite rude to others, mostly strangers and older people. He is also one of the quickest-thinking characters and often analyzes a situation with great ease and accuracy. Killua was born as the middle child of a family of known assassins, the Zoldycks.