Freddy Fazbear is the titular antagonist in the game, he will became on Night 3, and will go through the right door, and if you don't close, he will jumpscare you, he is also the animatronic that kills you when the power goes out.

Bonnie is a major antagonist in the game he is a rabbit like animatronic and will go on the left door, you need to close the door when he is in.

Chica is a major antagonist in the game, he is a chicken like animatronic and will go on the right door, you need to close the door when she is in.

Foxy is a major antagonist that stays in the Pirate Cove, and becomes active on Night 3, rarely Night 2, and stays leaving the Pirate Cove until he disappears, when you see he running, you need to look at the Left Hall, and than close the left door, otherwise he will jumpscare you.

Yellow Bear, know as Golden Freddy by the FNaF community, is a secret animatronic that can randomly appear in your office after fliping the camera, if you see a poster with he's face, "yellow_bear" is his name in the game's files.