Monster 6 appears as a tall, pale-skinned woman. She has a smile that almost stretches across her entire face, long black hair, and no eyes. She wears a black, floor-length gown with a dark red pattern on the front that resembles innards. Her hands are black and featureless except for her fingers, which are covered with blood.
Monster 6 is a secret monster encountered while going down the endless corridor in the basement. If the Protagonist walks down the corridor for a long period of time, she will slowly appear at the end. Once the player character is close enough to Monster 6, she will quickly rush towards them and kill them, displaying the following message on the death screen:
"Don't get up before Saturday."
Monster 6 appears in the main game's Endless Mode, being one of the many creatures who can randomly engage the player character in a chase. During the chase, a dark, foggy overlay limits the player's vision. Monster 6 deals around 1/3 damage to the Protagonist, and does not pause in-between her attacks, leaving little room for error. This makes dead ends and head-on collisions with her very hazardous.
"BEKKA AMB", Bekka's chase theme.
- She is the only Karamari Hospital enemy that cannot be killed with the Sword.
- She is also the only enemy from the DLC and the 4th enemy in game that can kill the Protagonist in one hit.
- Her corridor will still appear when Monster 4 chases the player character.
- Monster 6's name, appearance, and death screen are likely a reference to celebrity Rebecca Black and her infamous song, "Friday".
- She is functionally identical to Specimen 9's regular form, although the corridor does not close in on the Protagonist for her event.
- She is the only monster in the DLC that doesn't have a 3D model.