Paladin Gunny is in charge of training initiates and turning them into hard-nosed Knights and Paladins. He is unhappy with the Elder Lyon's method of taking on volunteers from the wasteland but still performs his duty to the best of his ability.
He can be found in Ring A just outside the lab in the council room, outside in the courtyard training recruits during the daytime, or inside a dormitory in Ring B.
"Gunny" is a play on the common nickname for United States Marine Corps personnel holding the rank of Gunnery Sergeant.
Sometimes, after completing the game when talking to him, the subtitles will say, "Nothing to report here," but he will say, "We've got this area locked down." This can also happen to unnamed Brotherhood of Steel members. [platforms tag needed]
Sometimes Gunny will appear without power armor, wearing a merc charmer outfit instead. [platforms tag needed]