1. The Puppet (The Marionette)
Stationed at Cam 11 (Prize Corner), the Marionette serves as the core pacing mechanism of the entire game.

Its music box unwinds at a speed proportional to the current night’s difficulty.

If the music box unwinds completely, the nursery tune "Pop Goes the Weasel" plays. Once the tempo accelerates, the Puppet departs its container.

At this stage, death is guaranteed; neither the Freddy mask, flashlight, nor monitor can stop its incoming jumpscare.

2. Withered Foxy
Withered Foxy serves as the mechanical counterweight to the Freddy mask. fnaf 2

Foxy completely ignores the Freddy mask; wearing it while he stands in the hallway actively speeds up his pounce timer.

To neutralize Foxy, you must pulse your flashlight beam directly into the corridor in short bursts (3 to 5 rapid taps). This flashes his optical sensors and resets his attack timer, buying critical seconds to service the Music Box.

3. Balloon Boy (BB)
Though Balloon Boy has no physical attack animation, he is arguably the most dangerous character on late nights.

BB crawls through the Left Air Vent. If your vent light catches his face peering through the grate, you must immediately put on the Freddy mask and hold it until the metallic vent thud signals his departure.

If BB slips into the office, he disables your flashlight and vent buttons permanently while laughing continuously. This leaves you entirely defenseless against Withered Foxy.