Sally is part of the garrison and, contrary to what may seem, is male. He does not like his name very much and envies the rest of the 'rrys. He does not break the theme of stupidity among the squad, although is a force to be reckoned with in combat.
↑Fallout Official Survival Guide p.93-94: "Harry: Super-Mutant Spy and Leader Harry is the leader of the super mutants protecting the water shed in the Necropolis, and as such, he is the one you're going to have to get past if you want to accomplish one of the principle goals of your mission. He is also a spy, keeping a close eye on Set for the Lieutenant. He is on the alert for any "normals," whom he will try to capture and take to his boss. He is one of the largest super-mutants you'll meet in the game, an enormous creature that makes the Terminator look like a skinny runt by comparison. Fortunately, he has one endearing trait: he is mind-numbingly stupid, and a smart player can turn this against him. Harry leads a group of mutants in guarding the water shed. Their names are Larry, Gary, Barry, Terry, and Sally. (Sally does not like his name very much.)"