The Sphinx of Games is a weaker spirit and minor character who guards a small "bridge" in a Mayview back alley. He is one of the major antagonists of Chapter 3, along with Johnny and Ollie.
His design and character is based on the Sphinx from Greek mythology.
Personality
The Sphinx has a rather bizarre personality, challenging passerby with strange nonsensical riddles and threatening to eat them should they get them wrong. It wildly overreacts to individuals (predictably) getting its riddles wrong, and will tenaciously pursue them should they escape.
Paranatural
The Sphinx challenged Isaac and Max as the two made their way to the shortcut. Isaac claimed he could easily overpower the sphinx and that they might as well try to talk it out. After getting the riddles incorrect the Sphinx attempted to attack Isaac but was quickly defeated. The Sphinx continued pursuing Isaac after he left claiming the rules of the challenge must be met, until Isaac informed him that the game was rigged and he had "shoehorned in" eating them after the first riddle. After learning this the Sphinx seemed to be genuinely surprised and left, claiming that "the others will hear about this."
Abilities
The Sphinx is a bestial spirit with the ability to fly and can move quickly, allowing it to efficiently hunt down its prey.
Gamesmaster
According to a comment of Zack's, the Sphinx's ability allows the conditions of a game it sets to inevitably come to pass. For example if the losing condition set for the player is "The Sphinx will devour you", and they fail to correctly answer the Sphinx's riddles it will eventually eat them regardless of what may happen. Likewise if the winning condition was "being able to cross this bridge", failing to correctly answer the riddles will prevent the player from crossing the bridge. However, the conditions of a game CANNOT be changed during the middle of the game; the only conditions enforced by the Sphinx's power are those set at the beginning of the game.