Grey Squad was a squad of nine clone troopers. This group of soldiers belonged to a platoon within the Grand Army of the Republic during the Clone Wars, a conflict between the Galactic Republic and the Confederacy of Independent Systems. Near the war's conclusion, Grey Squad found themselves stationed on the planet Mustafar, which is located in the Outer Rim. A Jedi Knight, a clone trooper sergeant, in addition to a clone trooper corporal, were the leaders of Grey Squad.
In 19 BBY, Supreme Chancellor Palpatine initiated Order 66. Subsequently, Grey Squad betrayed their Jedi commander and started to hunt him down. Although the Jedi Knight successfully evaded Grey Squad, he noted in a datapad that it was only a matter of time before him was caught. Anticipating their eventual arrival, he secured most of his personal possessions inside a chest for Jedi Master Yoda to discover. Around 1 ABY, a band of spacers found the datapad detailing Grey Squad's actions within the stolen goods of a bandit camp located on Mustafar.
The Star Wars Galaxies video game, specifically the Trials of Obi-Wan expansion, featured a quest called "The Jedi's Guard Dog" which made mention of Grey Squad. This massively multiplayer online roleplaying game was developed by Sony Online Entertainment, and was published by LucasArts on November 1, 2005.