Sylvester is an fan-made antagonist in Abandoned: Discovery Island.
Sylvester starts from Night 5. He starts in the Lounge off-screen. After minutes of being off-screen, he will become on-screen, standing behind one of the chairs. He will immediately go to the Office shortly after. The player must flip the monitor and must wait for a minute. Neglecting or failing to do so will result in a kill-screen and the game to crash.
Sylvester is heavily similar to Nightmare Photo-Negative Mickey, except that he has a dark blue face instead of pink, the spikes on his feet, the glove on his right arm, and his eyes are absent, has yellow blood on his left eye, and wears a white jacket, a black shirt, and a blue bow-tie.