C.H.U.D
Cannibalistic Humanoid Underground Dweller
is a 1984 American science fiction horror film directed by Douglas Cheek, produced by Andrew Bonime, and starring John Heard, Daniel Stern, and Christopher Curry in his film debut. The plot concerns a New York City police officer and a homeless shelter manager who team up to investigate a series of disappearances, and discover that the missing people have been killed by humanoid monsters that live in the sewers.
Will Menaker of Chapo Trap House podcast started using the term to describe alt right freaks and weirdos in the trump administration around 2017
Chapo subreddit picked up on the term and started using it to attack reactionaries in general.
Chudjak was drawn by leftypol and based off the mass shooter in Texas who targeted hispanics in 2019, Patrick Wood Crusius, who killed 23 people and got life without parole.
/pol/ picked up on chudjak and modified it from its original form to make other edits. Eventually there was the "billions must die" and "nothing ever happens" variants.
The Bulgarian name is unrelated.
https://en.wikipedia.org/wiki/2019_El_Paso_Walmart_shootinghttps://en.wikipedia.org/wiki/C.H.U.D.