Gack

Acronym: God-Awful Cornholed Kook

Usually referring to a person who participates in anti-social behavior. Can refer to, but is not limited to:

-Internet Trolls
-Anti-Furries
-Bloxheads (Toxic Roblox Players)
-Stans (Especially the ones obsessed with authoritarian/fascist/terroristic ideologies)
-Etc.

"That user there? I heard he's an anti-furry."
"Great, another screwball gack on the loose."