Or were you looking for Overclock's counterparts, Mad Endo or Gold Endo?
“Each guardian protects a button.”
— Fredbear talking about the guardians,FNaF World
Overclock is a boss and one of the guardians encountered in FNaF World. They're encountered in Deep-Metal Mine. They stand guard to one of the bottons that block the path to Security.
Overclock's appearance is almost identical to Endo-02's appearance, minus the skeleton-like head and the strange two-toed feet. Its body seems to be merged together, giving it a strange look. It is noticeable that if one looks closely, it has sharp claws. Mad Endo and Gold Endo have them as well, due to being just a weaker version with nothing changing in appearance and a recolor, respectively.
Overclock is one of the guardians that protects a button, the other ones being Supergoon and Snowcone.
In fact, all of them have weaker counterparts which look identical.
Overclock is the fastest character in the game.
This is most likely because the term "overclocking" is the process of configuring a computer processor or other electronic circuit to run faster than originally intended, allowing it to be faster and more responsive.
People used to think that the texture was different to Mad Endo.
People used to think that Overclock was angrier looking and had a faster animation than Mad Endo, however this is a myth and is not actually true as they both share the same texture in the files.