Birthday: July 7 Birthplace: Kukulu Mountain 
Nen type: Manipulative
Height: 158cm
Weight: 49kg 
Blood type: B
Hatsu: Change

Killua was born to a family of renowned assassins, the Zaoldyeck family. Showing great promise from birth, Killua has already mastered many killing techniques at a tender age, and is set to be one of the best assassins the family has produced. Bored and tired of killing, Killua unexpectedly rebelled against his family, injuring both his mother and brother, and ran away to join the Hunter exam. Meeting with Gon during the first obstacle, Killua saw Gon as a friendly competitor, and ended up becoming fast friends.

From the outside, Killua seems just to be the boy next door, cheeky, cheerful and full of mischievous ideas. However, his ruthlessness and aptitude in killing shows the other side of him--deadly, violent and bloodthirsty. Having been repeatedly tortured since birth, Killua has been conditioned to possess extreme tolerance for poison, electrocution and pain. Possessing both extraordinary agility and strength to match, Killua is one mean killing machine. However, his greatest flaw is to fear characters more powerful than him, like his elder brother.

As an Enka person, who can transform the nen into any substance at their will, Killua is busily practising this ability. So far, he has managed to successfully transform his surrounding nen into an electrically charged form, producing volts of electricity.