Sludgebrain 

An emotionally-stunted kind of person, the type to exclusively respond to everything with "wholesome", "valid", "oof", "mood", or "poggers" and nothing else, as if his or her brain has rotted into sludge. Sludgebrains are typically only found on the internet, and are extremely rare in the real world. A typical sludgebrain will usually have pronouns in his or her bio and a religious obsession with Animal Crossing or some shit.

Instagram is one of the internet's largest Sludgebrain colonies.

Sludgebrain by Some fuckwit somewhere November 28, 2020

sludgebanging 

A form of headbanging adapted for the sludge metal genre of music. It is a full body motion often performed with bent knees that involves an initial leaning-back followed by a vigorous lunging-forward motion in which the sludgebanger's head can come dangerously close to hitting the ground. Pro sludgebangers are known to be capable of bringing their foreheads to within 10 - 20 nanometers of the ground without contact.

Band members of the popular sludge metal band ISIS can be seen sludgebanging during live performances.

sludgebanging by Doug Grz January 21, 2008