'Mr. Phone Guy', our friendly guide in the popular online game 'Five nights at Freddy's', was n't directly killed by any particular robot. For most people playing the game, the best bet still seems to be that he was attacked by several machines at once on the fourth night. His messages live on, echoing their sad refrain of Golden Freddy's screech and Freddy's music box; it sounds as though the entire mob has ganged up against him.
But it's only a theory: one of many. The game itself is so obscure that players have no choice but to pursue the mystery, encountering fresh problems and gaining more questions than answers.