A bird-like animatronic. Parts of its legs and arms have exposed endoskeletons. Infected with the modified plague and isolated on the island, it feels forgotten. It harbors a strong grudge against humans, holding them responsible, and attacks on sight. It appears in various locations. There are multiple units, but they do not corner the player simultaneously. It does not speak.

The true mastermind. A special animatronic (essentially a robot) covered in a black, liquid-like substance. Male. It has mechanical parts on its chest and arms, but its head and other parts are composed entirely of the black liquid. It always wears a wide grin with white fangs and has red eyes. Created by Walter through experiments. It mimics others by wearing the corpses of humans and such. It hates light and moves through shadows, often emerging from the darkness. Uses a purple glowing sword during the final battle. "What do you think you are? Who do you think you're dealing with?"

A robotic gambler. Wears a top hat and a gold monocle over his left eye. He has a red bowtie at his neck. A slot machine in his torso is constantly spinning. He is missing his right hand. His head is a TV, and he expresses emotions similarly to Mr. TV. You must show him all your belongings at the start. He is unaware that he is infected. He gets attacked by Subject 01 and goes missing while stalling for time to let Guest and the others escape. "I'll hold this one back. I'll be back as promised—this is the ultimate gamble."

A support character. An ally who provides information about the facility. Has a human-like side, occasionally cracking jokes. Displays his face on a monitor to express emotions. "Be careful not to get electrocuted. I wouldn't want you turning into a dinosaur-shaped nugget."

The source of everything. Male. The man who modified the plague to infect both machines and humans, and the creator of Plug One. He can manipulate the black liquid found on Plug One's body. In the Happy Ending, he admits his crimes, has the vial destroyed, and meets his end after defeating Plug One. In the Bad Ending, he is dropped into lava by Plug One. "Did you have fun? Destroying my facility piece by piece?"

A mascot character. Cannot die. Can be petted. A yellow four-legged rabbit about the size of a cat. One ear is missing. Inhabited by a soul; after the Happy Ending, the soul departs, the light fades from its eyes, and it stops moving.

Konomi: Name: Konomi Amami First person: I (Kono) Gender: Female Personality: Kind, occasionally clumsy (PON) Address: "Kono~", "Konomi-chan" Species: Beastman Koma: Name: Koma Komawari First person: I (Koma) Gender: Female Personality: Energetic, loud, a playful brat Address: "Koma~" Species: Human Rako: Name: Rako Otonose First person: I (Rako) Gender: Female Personality: Bratty, but serious when it counts Address: "Rakochi~", "Rako-chan~" Species: Sea Otter Afraid of the roaming animatronics. Yura: Name: Yura Yuragi First person: I (Yura) Gender: Female Personality: Big-sisterly, calm, and kind Address: "Yura-nee~", "Yuragi~" Species: Moon Jellyfish Nufu: Name: Nufu Nijimi First person: I (Ore / Atashi) Gender: Female Personality: Kind, good at acting energetic Address: "Nufu~", "Nufuchi~" Species: Half-Mendako (Flapjack Octopus) Tsukuri: Name: Tsukuri Nemumo First person: I (Watashi) Gender: Female Personality: Seems easygoing, but actually isn't Address: "Tsukuri~", "Nemumo~" Species: Human Liz: Name: Liz Amaya First person: I (Liz) Gender: Female Personality: Like a big sister, but totally clumsy (PON) and always teased by Tsukuri Address: "Amaya~", "Liz-chan~" Species: Human Rei: Name: Rei Yugiri First person: I (Rei) Gender: Female Personality: Claimed to be the cool type, but that persona collapsed immediately Address: "Rei-chan~", "Rei-pyon" Species: Human Carries a sniper rifle. Nono: Name: Nono Otonono First person: I (Nono) Gender: Female Personality: Kind, big-sisterly...? Address: "Nono-chan~", "Nono~" Species: Human Akubi: Name: Akubi Demonspade First person: I (Akubi) Gender: Female Personality: Bratty, occasionally serious Address: "Supe-sama~", "Bee-sama~" Species: Demon Can use a little magic since she's a demon.