It is the lost endoskeleton of Bonnie.
Endo R is a withered endoskeleton. Its body is covered with wires, around the torso and limbs. The front of Endo R's face is missing, leaving only the bottom jaw, like Withered Bonnie's Endoskeleton head. Similarly, the left arm is gone, leaving a mess of wires in its place. Endo R's eyes are dim red pinpricks as well. He also sports a red wire around his spine.
However, unlike Withered Bonnie from FNaF 2, Endo R has a different head shape more similar to Endo..
Endo R first appears in the Basement. The player will see hallucinations, warning them that they aren't safe. The player must then return to the bathroom. Endo R only attacks if the player does not return to the bathroom in about 20 to 60 seconds.
Endo R later appears in The Attic, where he will approach from the right side. If the player hears running footsteps coming from the right, they must shut the right door to prevent Endo R from getting inside.
- The R in Endo R's name may stand for Rabbit, as it's implied to be a Bonnie Endoskeleton.
- Its second name may be a reference to Bonnie's fur color. Even if Bonnie IS a little purple, as well.
- It is unknown why Endo R does not enter the bathroom knowing that the player is inside.
- However, there is a glitch where Endo R will still come after the player even if they enter the bathroom.
- The only known way to fix this is to either restart the night or get close enough to the wall so that Endo R can kill the player. This has happened to the Youtuber 8-BitRyan. This can be found here.