A humanoid entity whose entire body and face are covered in gray concrete. His face is oval-shaped, and a glowing white eye is visible on the left. Looking into the holes scattered across his body and face, red tumors can be seen filling those spaces. Cysts also protrude from various parts of his body. When he first sees the player, he covers his face and backs away to avoid them, but if the player continues to look at him, he lets down his guard and rushes in to explode their face. Additionally, Crick attempts an assassination when the player's back is turned. If the player fails to look back within 3 seconds, their head is snapped 180 degrees, resulting in death.

A mold-type entity that inhabits various parts of the stairwell rooms. It can be seen covering the floors and ceilings of the stairwell, as well as in the form of lumps and tunnel-like structures. It also appears in the form of pits on the floor. Meld looks like red flesh embedded with things resembling white ant eggs. Lump Melds can be passed by flicking a white fleshy string, which causes the lump to open up and down. Applying fire will force the Meld lump open, allowing passage. Occasionally, it takes root and spreads its territory throughout the stairwell.

A mimic-type humanoid entity composed entirely of static noise. Noise's TV is guaranteed to exist somewhere in the stairwell rooms. If you approach the TV, Noise crawls out and follows the player's movements exactly. If the player stops, Noise's appearance turns a deep blue and he pauses as well. If the distance from the player increases, Noise's body turns blue and he closes the gap. If Noise's TV is pushed into stairs or a Meld pit, or destroyed by activating a fire alarm, Noise disappears immediately.

Small entities with human facial features and blue, green, or orange appearances. Stems are small entities that each possess a single human facial feature. Stems attack the player by rolling, and individuals with mouths will bite. Stems can merge with each other into humanoid, pillar, or T-shaped forms. Merged Stems cannot attack. If you roast Stems with a fire alarm, you can grind them in the shredder. Stems emerge from stairwell lockers. Occasionally, golden-colored Stems also appear.

A friendly humanoid entity with black skin, wearing a gray hood and bandages wrapped around his limbs. Cobbler's face looks like . | °. Upon reaching the 99th floor of the stairwell, he sells Starlight Jugs, Scanners, and Peach Cobbler. He can speak, but he uses his own language called "Cobblish."

A form of Noise that has become much stronger after being infected by ransomware. His entire body has turned into red noise, and a screaming face is visible on his head. When CD-1 is inserted into Noise's TV, Noise retreats back into the TV, the screen turns red, and Hijack appears. Unlike Noise, Hijack does not stop even if the player stops; he pauses only at random intervals. Unlike Noise, Hijack's speed is incredibly fast, making escape almost impossible. However, like Noise, if the TV is pushed into a Meld pit or down the stairs, it will be destroyed and Hijack will vanish.