Lost Ones

Appearence
The Lost Ones are high humanoid figures covered by ink with orange eyes.

Past
Very little is known about their past, but it's implied they were humans once.

Chapter 4: Cossal Wonders
They appears in various locations, like the archives, the room wit the access to the vents and the research and design area. They're totally passive with the player

Chapter 5: The Last Reel
They appears in their village. One of them fishes. They become aggressives and try to kill the protagonist Henry using Gent Pipes after Tom kill Sammy Lawrence.

Personality
They're sad and frightened. They aren't really bads and they want just to be free from the studio. It's possible that in the Chapter 5 that they angry with Henry, Allison and Tom for the death of their boss Sammy Lawrence and that's why they attack them.