The Knights who say “Night Cache”
The Knights Who Say "Ni!", also called the Knights of Ni, are a band of knights encountered by King Arthur and his followers in the 1975 film Monty Python and the Holy Grail. They demonstrate their power by shouting "Ni!" (pronounced "nee"), terrifying the party, whom they refuse to allow passage through their forest unless appeased through the gift of a shrubbery.
The knights appear silhouetted in a misty wood, wearing robes and horned helmets; their full number is never apparent, but there are at least six. The leader of the knights, played by Michael Palin, is the only one who speaks to the party. He is nearly double Arthur's height, and wears a great helm decorated with long antlers. The other knights are large, but of human proportions, and wear visored sallet helmets decorated with cow horns. The knight explains that they are the "keepers of the sacred words 'Ni', 'Peng', and 'Neee-Wom'." Arthur confides to Sir Bedivere, "those who hear them seldom live to tell the tale!"