David's friends

Cookie1, 'Knobby' is a tag, not a nickname. The referenced guy is probably the one who handles doors when the group breaks into places, for entries and exits. There is another friend of David's called 'Hacker', and I'm sure that a similar idea applies to him in the case of computers. Knobby is much more relaxed than his roommates are, but a criminal nonetheless. He is afraid of David and Logan, especially since those two constantly fight for the position of leader, and tries to appear respectful when talking about how everyone in the house has to leave shortly. Perhaps a few of the guys have spotted each other doing different illegal things at the same time and David has stumbled upon the formed group after being evicted from wherever he is sent to as a teenager. Knobby objects to injuring others which is why he hangs in the background when the gang vandalizes the Walker home. Notice how eager the calm member is to leave the scene and take Hacker to an emergency room. He doesn't want to live with the violent bunch, but must not have any other residence to go to.