The Nightmare Realm is a parallel world inhabited by beings of strange unimaginable weirdness in the television series Gravity Falls. It was the former settlement of Bill Cipher and his demon allies. Those who reside in this world are granted access to the dreams of humans.
- Bill Cipher (formerly)
- 8 Ball
- Amorphous Shape
- Lava Lamp Shaped demon
- The Horrifying Sweaty One-Armed Monstrosity