Lillua Zoldyck is usually friendly but he doesn't like strangers and He HATES chimera ants. He usually hit his enemy with Big blue piko piko hammer which is a Giant Hamlet. 

Lillua is An Inventor, a Scientist and an Assassin at the same time. He is Close with Gon Freecss amd of course his twin brother Killua Zoldyck
and he owns Robot Animals. Aibo the Robot dog, Ava the pink robot dog and MarsCat the robot cat 

Watch out if you're gonna ask a handshake or a hug from him. He may be young