The sound comes from the Knights Who Say Ni sequence in the 1975 comedy film Monty Python and the Holy Grail. In the scene, the bizarre forest knights repeatedly say “Ni” and demand a shrubbery from King Arthur’s party. The cry became one of the film’s best-known quotations through repeated viewing, fan references, sketches, and online edits. Its minimal length, unmistakable delivery, and deliberately nonsensical meaning keep it useful as a quick reaction sound for absurd demands or unexpected interruptions.