Specimen 10 is a parasitic alien lifeform. Before encountering the player, this creature lived inside the old Specimen 10. It was the cause of the abandonment of the GL Labs's Facility starting from Room 610.
Specimen 10 has two forms:
The 1st form resembles a female, armless humanoid figure with a deformed upper body that seems to be composed of 2 parts: the yellowish organic layer that covers the entire upper body, and the main body with no arms and bare humanoid legs.
This appearance is also included in its form where its torso opens up into two parts that make an opening with small teeth surrounding the inside walls of its apparent mouth.
The 2nd form resembles a large, leech-like creature. This form retains the same colors as the 1st form. Similar to the old Specimen 10, the 2nd form is divided into separate segments, which slither along the ground. The inside of this form has at least two visible sets of teeth.
Specimen 10 appears in Room 617 after the player uses the generator. At first sight, the player sees the old Specimen 10 coming out of the vents, crawling towards the player. However, shortly afterward, the actual specimen erupts from the head of the latter, killing it. Now the new Specimen 10 begins to chase the player. This specimen cannot go through walls and moves rather slowly, although slightly faster than Specimen 5. It comes out of the door fast.
If the player gets too close to Specimen 10, it will reveal its huge vertical mouth in its torso and attack the player, dealing approximately 40 damage while causing constant disturbing visuals at the same time. Because of how slow it is, the player can usually outrun this specimen. However, if the player runs out of sight of Specimen 10 for a few moments, the creature will give a flashing screen as a warning before transforming into its 2nd form, in which Specimen 10 can move quicker. It now deals roughly 20 damage to the player and disturbs their vision.
Specimen 10's attacks leave the player's vision covered with a yellow, slimy substance for a period of time. The more damage taken by its attacks, the thicker the substance becomes. This substance will slowly fade away after a period of time. It should be noted that hitting Specimen 10 with the axe can force it to transform into its 2nd form. In this form, the axe is useless against it.
When the player is killed by Specimen 10, they will be presented with a flashing screen, with text reading:
"Now you have nothing to fear.
Now you have nothing to think.
Follow your selfish desires.
Follow your natural instinct.
After all you're just an animal.
It's much easier than trying to think."
During this sequence, the player can briefly see the hidden binary code behind the notes:
01011001 01101111 01110101 00100000 01100001 01110010 01100101 00100000 01101101 01101111 01110010 01100101 00100000 01110100 01101000 01100001 01101110 00100000 01101010 01110101 01110011 01110100 00100000 01100001 01101110 00100000 01100001 01101110 01101001 01101101 01100001 01101100 00101110 00001101 00001010 01010101 01110011 01100101 00100000 01110100 01101000 01100101 00100000 01110011 01101111 01110101 01101100 00100000 01111001 01101111 01110101 00100111 01110110 01100101 00100000 01100010 01100101 01100101 01101110 00100000 01100111 01101001 01110110 01100101 01101110 00101110 00001101 00001010 01000001 01101110 01100100 00100000 01100010 01100101 00100000 01110010 01100101 01110011 01110000 01101111 01101110 01110011 01101001 01100010 01101100 01100101 00100000 01100110 01101111 01110010 00100000 01111001 01101111 01110101 01110010 00100000 01100001 01100011 01110100 01101001 01101111 01101110 01110011 00101110
...which translates to:
"You are more than just an animal.
Use the soul you've been given.
And be responsible for your actions."
"Getting There", Specimen 10's chase theme.
- The current Specimen 10 is the only Specimen that has replaced another Specimen (The old Specimen 10).
- Specimen 10 is also the first specimen that is unofficially believed to be an extraterrestrial life form. It may have been inspired by Dead Space's Necromorphs, which were parasitic aliens, or by John Carpenter's the Thing.
- Despite the parasitic nature mentioned in the CAT-DOS, Specimen 10 in-game cannot latch onto the player to damage them. This is perhaps another tie-in with the Necromorphs, which had to kill their prey before the parasite could take hold and mutate the body to a suitable vessel.
- Specimen 10's CAT-DOS entry can only be seen once the player has made it past room 500.
- However, this specimen has 2 CAT-DOS entries, its actual entry, and the original Specimen 10's entry. The player has a 50 percent chance of seeing one or the other.
- It is the second specimen to have a hidden binary message, the first one being Specimen 11.
- Intriguingly, the hidden binary message of Specimen 10 contradicts the notes showing on its death screen.
- In the CAT-DOS entry for the old Specimen 10, it is implied that a certain specimen led to the abandonment of the facility. This is very likely the doing of the new Specimen 10, as the glitched-out entry of the old Specimen 10 noted an error that made the entry display the wrong specimen.
- It is possible that the current host for Specimen 10 was one of the GL Labs' Assistants trying to retrieve the loose specimen, as the last note in the Facility's vents stated that "he/she was hiding from that thing" and "something was growing on his/her skin" and "he/she couldn't seem to tear it fast enough and was losing a lot of blood".
Specimen 10 appears to be a large, floating worm. It is made of various distinguishable segments. Specimen 10's front-most segment appears to have black eyes and, in its gaping mouth, many sharp fangs. Its skin is pale and appears to be slimy.
Gameplay (before 2.7.1)
Before the 2.7.1 update, Specimen 10 appeared around Room 617. After the player used the generator, it would begin to chase the player.
Hitting Specimen 10 with the Axe didn't harm it-- it only made a noise.
Specimen 10 dealt about 20-30 damage on contact. It crept rather than float and was quite slow. It could not go through walls either.
According to its old CAT-DOS entry, Specimen 10 was active, and its fatalities were 46.
Following the 2.7.1 update, it returns as a passive specimen, as stated by the CAT-DOS:
"A worm-like creature that inhabits the old rundown GL labs. A genetically modified eel that was supposed to be extremely violent but instead was very passive. Though not effective it was kept as a pet until the facility was abandoned due to specimen ????"
In the game, it somewhat served as a host for the parasitic Specimen 10. When the player sees Specimen 10 crawling out of the vent, it will not attack-- instead, the new Specimen 10 will pop up from the latter's head, killing it, and start chasing the player.
Specimen 10's awakening sound.
Sounds that Specimen 10 makes when hurting it with the axe.
Sounds which can be heard when Specimen 10 is near the player.
- Rarely, Specimen 10 can leave the map and can't return due to its inability to pass through walls. This is fixed once the player enters the next room.
- Before the 2.7.1 update, the developers of the game planned to remove Specimen 10 from the game entirely.
- It was an aggressive specimen before being replaced by its current form.
- Specimen 10 doesn't have a death screen along with Specimen 3 & Specimen 7.
- Specimen 10 shares the same chase music as Specimen 3.
- The CAT-DOS entry for this specimen can only be viewed before reaching Room 500.
- Its entry also seems quite glitchy. The glitched-out info implies there was an error that made it show the wrong specimen: the correct one was the new Specimen 10.
- Specimen 10 (old) will not deal damage to the player when it comes in contact with them in the new update. However, it leaves the player vulnerable to damage from the new specimen.
Spec 10 Old
The specimen now has an animation for opening its mouth.
The hallucinations seems to display much faster with no sound. The specimen also moves faster than in the original. In addition, the second form now deals as much damage as the first form.
- If Specimens are disabled, the old Specimen 10 still appears and its head rupturing animation still plays, but nothing else happens after that, and the new Specimen 10 doesn't spawn.