|Special||First Halloween-themed skin|
Horror is the fourth selectable site skin, released in October 2008. All Nitrome characters featured in Horror are dressed in a Halloween fashion, in the form of monsters, zombies and vampires. Nitrome Towers can also be seen in the background.
In the background, Nitrome Towers can be seen in a graveyard, in front of a full moon. Beside it, Magneboy is seen poking out of the ground, and beside him is a zombie-like guard infested with maggots, standing. The red feather tribesman is walks away from the guard, also acting like a zombie, with maggots stuck to his head.
On the right side of the skin, Poly sticks his head out of the ground. To Poly's right is a basic cyber guard acting like a vampire. Toxic is also seen without his visor and two orange eyes in his head area. Up in the tree are both the cat and dog from In The Dog House, acting like ghosts, the big hat pirate ghost, the owl from Fat Cat looking ghostly.
Some tombstones hinted sequels for certain games. Next year Final Ninja Zero was released, which was hinted by the FN 0RP tombstone. Close to the end of 2008, Nitrome released Frost Bite 2, the sequel to Frost Bite, Frost Bite 2 being hinted by the tombstone that reads FB?.
Featured in the skin was a character called the weresquare, who was slated to appear in Square Meal 2, but because Square Meal 2 was temporarily shelved and forgotten about until 2012, the weresquare was never shown outside of Nitrome.
- Every character appears to be a zombie in the skin, except the brain and weresquare.
- Horror and Factory are tied for having the least amount of characters of all the skins Nitrome has ever made, each skin having thirteen. The winter skin is the second-most skin with the least characters, having only fourteen characters (not including the two eskimos).