Nightmare Squadron consisted of Rebel Alliance T-65B X-wing starfighters and was stationed at Titan Base, which was an underground starfighter installation situated within the Corva sector. Around the time of 0 ABY, this squadron was primarily engaged in missions within neighboring regions, having earned notoriety for swift and devastating assaults on Imperial objectives. As an Alliance Special Operations unit arrived to execute a mission aimed at sabotaging the Empire's Operation: Shell-cracker, the squadron, under the command of Jayce Terril, was getting ready for what he referred to as an ambush double, involving a micro-jump to a different location. Soon after, the squadron entered hyperspace heading to The Hammer to provide support to the team in their attempt to seize the Shell-cracker prototype and engaged in combat with Alpha Squadron.
The adventure "Operation: Shell Game," found in Fantasy Flight Games' Star Wars: Age of Rebellion Beta, features Nightmare Squadron.