Chunk was a Coates kid with no powers. He served Caine, who - when he wakes up from a coma - goes mad and slams him through a brick wall, killing him. Chunk only appeared in Gone but is mentioned in Hunger.
When he was alive, Chunk was described as chubby and extremely annoying, telling everyone about the famous people he'd met, because his father was a talent agent. He got on everyone's nerves, to the point where Caine "threatened to hand him over to Drake" if he didn't shut up. In the end, Diana explains that Chunk "looked like roadkill" after being thrown through the wall.
Chunk is described as being a Chinese kid. He is quite chubby. Not much else is known about Chunk.
Chunk tries to boast and impress everyone, but ends up annoying them. He boasts about all of the famous people him and his dad have met, because his father is a talented agent.