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 player walks down the corridor for a long period of time, she will slowly appear at the end. Once the player is close enough to Monster 6, she will jumpscare and kill the player, leaving a message:
"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 in a chase. During the chase, a dark, foggy overlay limits the player's vision. Monster 6 deals around 1/3 damage to the player. Monster 6 does not pause in-between attacks, leaving little room for error. This makes dead ends and head-on collisions with Monster 6 very hazardous.
"BEKKA AMB", Bekka's chase theme.
- She is the only 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 player in one hit.
- Her corridor will still appear when Monster 4 chases the player.
- Monster 6's name, appearance, and death screen could be 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 player.
- She is the only monster in the DLC that doesn't have a 3D model.