Yenndo is a bare Freddy Endoskeleton.
When using the beacon in Funtime Auditorium on Night 3, the player has a very rare chance to encounter Yenndo instead of Funtime Foxy. When spotted, Yenndo will stand still with three total positions rather than twitching, unlike Funtime Foxy. He seems to look at the player as well, and wouldn't attack nor jumpscare them.
In the non canon Custom Night, Yenndo acts similarly to Golden Freddy from the first and second game. At random moments throughout the night, Yenndo will appear on the right side of the Private Room after closing the monitor. He completely disregards the doors, appearing whether they are open or closed. When he is in the Room, the Oxygen bar will quickly deplete until it reaches zero. The moment the player sees him, they must bring up the Monitor. Doing so will cause him to disappear. If the player doesn't open the monitor before the Oxygen meter completely depletes, Yenndo will jumpscare the player.
Night modes where Yenndo is active are listed as follows:
- Funtime Frenzy
- Freddy & Co.
- Top Shelf
- Golden Freddy
- The Name Yenndo was first found in the Game files, as a portmanteau of Yellow and Endoskeleton. This was later shown to be his full name in Custom Night.
- Given that Golden Freddy was named Yellowbear in a similar way, this has led fans to theorise Yenndo was once Funtime Fredbear.
- Yenndo resembles Funtime Freddy's Endoskeleton, albeit with both hands, and yellow eyes.