Clumps are hostile entities which resemble massive clumps of human arms which flail about and extend in every direction. They are known to inhabit vents, cabinets, and other tight spaces. These entities are infamous for their uncanny level of intelligence when it comes to ambushing and preying on Wanderers.
These entities spend most of their time tucked away in tight spaces like closets, drains, pipes, chimneys, and most commonly, vents. Generally, the only part of a Clump which is seen by a Wanderer consists of it's frontal arms, which they allow to hang freely and dangle from within their hunting space, a behavior theorized to serve as a form of "bait" to get Wanderers to approach them. While occasionally an arm will flex or a hand will clench, these arms are generally immobile when no Wanderers are present.
When not in hiding, Clumps will take great care to avoid all contact with other entities or humans and remain mostly sedentary while they wait for prey to approach them. However after extended periods of time without food, these Clumps have been known to migrate to other Levels of the Backrooms, moving forward by propelling themselves with their arms at speeds of up to 20 mph, making them relatively fast in comparison to other entities, though they rarely display this ability.
Instead of chasing after prey, Clumps prefer to lay motionless in wait for Wanderers to come within their vicinity. Once they sense a Wanderer is close by, Clumps will begin to perform a number of movements in order to entice them into approaching it. These movements may include waving, clapping, snapping, pounding on the walls, communicating in sign language, and other sorts of hand gestures. Do not be fooled, as going anywhere near to a Clump is likely to swiftly end in your demise. If you see a Clump, slowly walk the other direction without being noticed (in some severe cases, you may need to run), also, keep your eye on the Clump to make sure that it doesn't do anything, and try not to make any noise while backing away, in general, you must stay at least 8 or more feet away from it otherwise you could be grabbed in and receive your terrifying fate.
An image of a clump Hiding in a vent