A particularly strong or annoying enemy in a singleplayer video game, typically a boss or other non-recurring entity.
Guy playing video games: "God, this boss has killed me like ten times now!!"
Guy's friend: "That's a Big Oof Nibba right there. Sorry, man"
Guy's friend: "That's a Big Oof Nibba right there. Sorry, man"
by captconan May 11, 2018