Endoskeleton/Canon

An endoskeleton is the internal metal skeleton of an animatronic. They usually vary by game and multiple bare endoskeletons can be seen throughout the series.

Sister Location
In this game, each animatronic has their own unique endoskeleton. Their designs are much more complex than the ones from the previous games.

A version of Funtime Freddy's endoskeleton with yellow eyes can rarely show up as an easter egg during Funtime Foxy's section. This mysterious endo later appears as a threat in the game's custom night, where it's revealed his name is Yenndo.