Kevin is one of the monsters seen on the whiteboard. Nobody bets on him. Even so, it is revealed that a film strip in the cellar was the artifact that was going to release him. The reason for it being a film strip is unknown.
Physical Description & AttributesEdit
He is not seen during the Purge, but it has been revealed that there was a deleted scene showing him. In the novelization, Kevin is described as a quiet, normal-looking person with a small smile on his face who calmly walks through the post-Purge chaos, until he comes across an injured guard and then proceeds to "exsanguinate him in a second." When Dana finds the guard, he appears "untarnished, but Dana had never seen "anyone more dead." Due to his normal appearance, any normal looking human seen in the purge could be Kevin.
Kevin is a sweet-looking guy that appears blandly normal and looks very kind, but he actually is a psychotic killer who exsanguinates and dismembers people.
A film strip would summon him if someone looks at the entire strip.
Kevin may be a reference to Sin City's Kevin, who fits the same description. Also, he could be a homage to Peter and Paul from Funny Games or even Dexter Morgan. A popular Canadian cartoon called Kevin Spencer also exists. The show takes place around Kevin and his alcoholic, sociopathic tendencies.
Director's comments reveal it is most like the character "Kevin" from the novel "We Need to Talk About Kevin", in which the child Kevin displays sadistic violent tendencies.