Ribseer is a boss entity in The Lost Floors, serving as the first boss of The Attic section.
Appearance
Ribseer bears a striking resemblance to Seek, being a skeleton infected by the latter's goop, just like the Stalkers. Ribseer is, however, more imposing than the Stalkers, with sharp bones protruding from the goop. Its skull bears Seek's eye as well as a mouth filled with sharp teeth. Ribseer's ribcage can also be seen.
Behavior
Most of the time, Ribseer aimlessly roams The Storage Room, sometimes stopping and turning back a few seconds after. It cannot hear like Figure, but Seek's eye gives him a deadly vision: if it spots a player, it will emit Seek's scream before chasing them until it catches them or they get out of its line of sight, at which point it will go back to roaming the room.
A crucifix can be used on Ribseer, but it will not fully banish it, only stun it for a few seconds. Players can also use a Flashbang to temporarily stun Ribseer.
Once players venture deep enough into the Storage Room, Ribseer will emerge from the ground and begin patrolling.