The Beard of the Mountain Cat (山猫の髭 Yamaneko no Hige) is a group of knights garrisoned at the base of a mountain, Trello, near the small inconspicuous Kaynes Village. They claim to serve directly under a Holy Knight and are also known as the Wildcat's Beard.
Upon getting a notice about the Rust Knight being in Boar Hat, and possibly being part of the Seven Deadly Sins, the knights, lead by Alioni, intending to arrest him, demand that the owner and the Rust Knight come out. The former didn't do so, which lead Alioni to presume that he was frightened expecting the owner to be an old man; however, Meliodas promptly came out, surprising them. He then demands that the Rust Knight come out as well, only for Hawk to come out pretending as him. Insulted and angry for being ridiculed and mocked, the knight lifted Meliodas by his collar. Just then, he was notified by one of his subordinates that a woman had escaped from the back door.
Upon assuming her to be the infamous Rust Knight, Alioni led the other knights to capture her, instructing them to not led their guard down, and telling them that they only had to corner her till Twigo arrived and that the reputation of the knights of Beard of the Mountain Cat would increase if they captured a member of the Seven Deadly Sins. While the knights were chasing her in the woods, Hawk started to defeat them one by one by charging from behind, and then quickly pushed Alioni from the cliff. Alioni was later saved by Meliodas, when Twigo cut a part of the cliff, which would have crushed him.