Specimen 13 resembles a young woman with shaggy, grey-blue hair. Before the chase, she is seen sitting on a floating crate, with her back to the player, wearing a towel around her waist. She reveals her true form during her death screen, where she morphs into a black-eyed aged woman with long sharp teeth.
Specimen 13 lurks within the flooded rooms. She quietly sits on top of a floating crate. When the player gets too close, she will dive into the water and the chase will begin.
Specimen 13 deals 15 damage with a half a second cooldown.
Specimen 13 will only move when the player is standing in water. The Specimen itself isn't visible and can only be detected through the loud splashes she makes when moving. When the player stands on a crate, she won't move and will be unable to harm them. When the player goes back into the water, she will resume chase, although she will do so farther away than her last splash, preventing her from dealing unavoidable damage if she stopped moving too close to the player. Specimen 13 will not pause between attacks, leaving very little room for error.
Once the player gets hit enough times, the screen will cut to Specimen 13's hair covered face, with bubbles appearing on screen, as if the specimen is submerging and drowning the player. The screen will then flash red a few times and show Specimen 13's true face before fading to black.
"Something In The Water", Specimen 13's chase theme.
Sound that plays on Specimen 13's Death Screen
- Specimen 13's behavior is a reference to Kaernk from the horror game Amnesia: The Dark Descent.
- Specimen 13's CAT-DOS entry, when accessed, may randomly show her face obscured by her hair or her true face.
- Specimen 13 can only be encountered once, along with Specimen 7.
- Specimen 13 cannot reach the player while they are on top of one of the crates, despite the fact that she can be seen sitting on top of a crate before the chase.
- Specimen 13, along with Specimen 7, are the only two specimens from the original game not found in Endless Mode.
- Specimen 13 may represent the Sirens found in Greek mythology.
Specimen 13's towel was replaced by what appears to be a fish's tail, and she now has a full 3D model. She is wearing nothing on her top half. She now has a diving animation for when dives into the water when the player gets close, but is still invisible when chasing the player.
The attacks deals 45 damage, killing the player in 3 consecutive hits, but now there is a 3 second pause between each hit. She also appears to move slightly slower.