Subject 1

Subject 1 is the main antagonist of Subject 4.

Appearance
Subject 1's appearance as a human is unknown.

Subject 1's original mutated appearance is unknown.

As of night 3, Subject 1 is shown to be bright red, and is covered in feather-like quills. In multiple locations, the skin has decayed, showing glimpses of a skeleton, most notably in the protruding shoulder and exposed ribs. One arm is larger than the other, mainly due to it still regenerating after the previous night. Scars, stitches, and wounds, can be seen all over the body. Subject 1's fingers are sharpened, also resembling quills, and the feet resembling that of a bird. His brain is partially exposed, with dried blood outlining the location. The bright red eyes are surrounded by giant sockets. Subject 1 is toothless, instead having a beak that moves akin to a puppet.

In night 5, Subject 1 looks very different, seemingly shriveled and broken. One of the arms is missing, with small wire like structures taking its place. The eyes are also shown to be slightly crushed.

In the berserk state, Subject 1 looks similar, but is slightly discolored, with black eyes instead of red, bones being recolored, and the body being a darker red.

Personality
Unlike the other monsters, Subject 1 still maintains memories of his humanity, making him a failed experiment.

Due to his experience, Subject 1 is in general paranoid and distrusting, to the point of initiating betrayal himself out of fear of experiencing it.

Subject 1's main goal is to destroy Mace Arms to prevent more freaks like him from existing. He sees the protagonist as a nuisance in this regard.

Due to mutation, Subject 1 is also very unhinged, being extremely prone to violence and anger.

Subject 1 has a feral/berserk mode, which can be activated under extreme emotion. In this state, Subject 1 is just as monstrous as the other creatures.

He sees himself in the protagonist, and repeatedly tries to give the protagonist a way out.

Powers and Abilities
Subject 1 has a few powers and abilities, the most notable one being regeneration, though this may take a toll on the rest of the body. Subject 1 also has enhanced strength and the ability to project his quills like a porcupine. These quills can be used to spread a dormant strain of Toxadoma Avii.

Gameplay
Subject 1 has at least a voice appearance in all but part 6.

He has a speaking appearance in parts 1 and 4 and is mentioned in part 6.

He attempts to attack the protagonist in part 2, who chops the hand off with an axe.

In part 3, Subject 1 has a major appearance, talking and taunting the protagonist at the end of the room, keeping a distance in particular to avoid confrontation. He does not have a full body appearance again until part 7.

In part 5, Subject 1 impales the protagonist, injecting Toxadoma Avii into his bloodstream, and seemingly kills the protagonist, though the protagonist is later shown to survive.

In part 7, Subject 1, shocked at the protagonist surviving, goes berserk, and crawls towards the protagonist, who must run and deactivate the nuke without dying.

If this happens, Subject 1 finally gives out, and welcomes the release of death before imploding, releasing quills all over the surrounding area.

Trivia

 * Subject 1 is based off the chicken creature in the game Repulsed.
 * Subject 1 was originally supposed to die in part 5, but this was scrapped due to wanting to see more of the character.