Cursed Fast Fredbear from Those Nights at Fredbear's Add-on 1.21+

Now the game features a unique animatronic, Freddy, who creates a constant sense of being hunted. The mod Cursed Fast Fredbear from Those Nights at Fredbear's introduces a creature with massive health, swift attacks, and the ability to instantly close the distance. This greatly increases the difficulty and completely changes the usual perception of Minecraft, especially for those who love a dark atmosphere.

Once he spots you, there’s almost no escaping — he runs faster than Officer Earl and can kill the player in just one hit.