The Mutant

The Mutant is basically a mutated Mouse. He has no viewing area in the Vents except when you see him in the Vent in the Office

Nights
He Appears on Night 3 and So on, but missing on Night 6.

Starting Point
He Appears in the Ceiling Vent, which has no Cameras

Detailed Description
He Looks like the Face, but missing an Arm and has two arms Conjoined on the other side, and his missing one ear, hes in the green side of the color palette

Trivia

 * The Mutant is the only character that stays in the Ceiling Vent.
 * The Mutant and Sorrow are the only ones with added Limbs.