Nightmare Fuel / Incarceron
- Incarceron is running out of organic resources, so sometimes people and animals are 'born' with mechanical parts. And organic matter is recycled.
- Finn's memories of his first few years there.
- Though rare, some people are literally born via Incarceron.
- Finn encountering the Beast in the Cave.
- The Half-Men are people who have been "repaired" by Incarceron with robotic components.
- The Chain-gangs are groups of people fused together and sharing a consciousness. They assimilate their victims.
- Incarceron and its eyes are everywhere, it can speak to you at any time, and it's very proficient at breaking people.
- If Incarceron were to Escape, the entire prison would suffocate, freeze, and die in darkness.