TDS 666 DEMON is a suit in Abandoned: Discovery Island.
In his passed life,TDS human, having the appearance similar to Jake's, but no information is known for what he actually looked like before being murdered. In his after-life(After being killed and remade by True Mickey),TDS spirit inhabits a damaged mouse suit, with a missing right arm, damaged,across his body, this is most likely due to his strong instinct power.
He rarely appear's in the office at any night. When he appears, the player has nothing to do to stop him, he is invincible to everything. If the player is using the monitor while he appears, he will admittedly close the monitor automatically, and will prevent the player from opening it.
After a thew minutes of being in the office, he will jumpscare the player, resulting in a game over.