The Cooper Clan is the most successful lineage of master thieves in history. Numerous grand heists have been performed by various Coopers throughout history, occasionally through assembling other thieves around them to form a Cooper Gang.
Notably enough, the Cooper Clan is also one of the most honorable lineages of thieves; Coopers steal only from those undeserving of what they possess, due to underhanded dealings or more sinister arrangements. A pervasive code of honor binds each Cooper, as the general ethos of a Cooper heist is to deprive the real criminals – there is "no honor, no challenge, no fun in stealing from ordinary people." As INTERPOL Inspector Carmelita Fox puts it, the Coopers and the police work towards the same goal on different sides of the law.
The Cooper Clan has often clashed with criminal organizations due to its honor code, including the Fiendish Five and the Klaww Gang. They have also bumped heads with rival thieves, such as Clockwerk or the Le Paradox Clan.
- Sly Cooper - The most recent master thief, Sly is the son of an honorable Cooper that went down fighting while protecting the Thievius Raccoonus. After the death of his parents, Sly was placed in an orphanage where he met his pals, Bentley and Murray, who he would later create their own Cooper Gang with. He defeated Clockwerk and Cyrille Le Paradox, two major enemies to the Cooper Clan. He also defeated Neyla, a corrupt Interpol agent who planned on becoming immortal, and Dr. M, a member of Sly's Fathers gang who attempted to steal the contents of the Cooper Vault.
Other major members
- Bob Cooper - The very first Cooper, Bob was a thief from Gungathal Valley, sometime around the year 10,000 B.C. He stole pterodactyl eggs as food for his tribe. His major contribution was the invention of the tool that became the very first Cooper Cane. His special in-game ability is being able to climb on icy surfaces, but cannot do common Cooper moves such as the Ninja Spire Jump or Rail Walk.
- Slytunkhamen Cooper I – Sly's ancestor from Ancient Egypt circa 1350 B.C., he was the father of Slytunkhamen II and the creator of the Thievius Raccoonus. His signature ability was to turn invisible to aid in stealing from corrupt Pharaohs and greedy noblemen. He was the first known ancestor before the Cooper Gang's escapades in the Ice Age.
- Slytunkhamen Cooper II – Sly's ancestor from ancient Egypt circa 1300 B.C., and creator of the Cooper Vault. He had two canes that bore a striking resemblance to the Egyptian Khopesh. He was skilled at creating the traps that were used in ancient Egyptian tombs.
- Salim al-Kupar – Sly's ancestor from Arabia, circa 1001 AD, Salim is said to hold the stealth of 40 thieves. His weapon was a sword with a curved, hooked blade – sporting a scimitar-like look, but with a much thicker blade. Naturally, he wore a turban in his Cooper Vault portrait. He has perfected a move called the Cobra Climb ability and owns a magic flying carpet.
- Sir Galleth Cooper - Sly's ancestor from the Medieval age, circa 1300 AD. He was an honorable knight and cunning thief who fought with a lance featuring a hook point. In this game it is shown that he perfected the wall hook climbing technique. He was also able to smash through barriers to get to his next point using the Catapult Crash.
- Slaigh MacCooper – Sly's ancestor from Scotland. The strongest of all of the Coopers, he could break any lock with a single blow using his large stone cane. He was the Cooper who created the wall-edge sneak.
- Rioichi Cooper – Sly's ninja ancestor from Feudal Japan, circa 1600 AD. He created the Ninja Spire Jump and implemented Japanese artwork of himself in his part of the vault. His weapons were two small canes, resembling hooked sais. He used the Spire Jump to sneak into heavily fortified castles in Japan.
- Henriette "One Eye" Cooper – A woman who sailed the seas circa 1616 AD and stole from other pirates. She had the innate ability to smell gold. Originally wielding a hooked dagger, she lost a hand and replaced it with a hook shaped like that of the trademark Cooper cane.
- "Tennessee Kid" Cooper – Sly's outlaw ancestor from the nineteenth century Western United States, circa 1884. He carried a six-shot revolver with a hooked handle. Tennessee Kid also invented the rail walk and rail slide. He used these to his advantage, due to the fact that there were many train rails all over the land.
- Thaddeus Winslow Cooper III - A Cooper from Victorian-era London, circa 1893, who was the most "gentlemanly" thief and a master of disguise. He had a cane similar to Sly's; the only difference is a red ruby-like gem at the end of its hook.
- Otto Van Cooper – An ancestor of Sly's from Germany who was a genius mechanic and skilled fighter pilot, much like Penelope. Due to his physical ineptitude, he used his talent to pull off heists with his machines facilitating his thievery. He kept some of his technical blueprints in the Thievius Raccoonus. The propeller blades of his biplane were shaped like the trademark Cooper hook.
- Sly's Father – He used the same cane that now belongs to Sly. Before being killed by the Fiendish Five, he pulled heists with Jim McSweeney and Dr. M, and created a technique to slide along lasers. He is seen as nothing more than a silhouette throughout the series. He did not write his "Laser Slide" move in the Thievius Raccoonus; rather, Sly learned the move while in the Cooper Vault.
The Thievius Raccoonus is an ancient book, in which every Cooper Clan member since Ancient Egypt has recorded their thieving escapades, in addition to instructions on their various moves. It was created by Slytunkhamen Cooper and was then passed down through the family for generations, but was later stolen and divided among the Fiendish Five on the day Sly was to inherit it. After 10 years, Sly tracked down the criminals and recovered the Thievius Raccoonus, afterwards recording his own adventures in the great book. After Sly left the life of a thief behind to strike up a relationship with Carmelita Fox in Sly 3, the book fell into the care of Bentley, who became the first non-Cooper in history to write in the Thievius Raccoonus.
The Thievius Raccoonus again fell victim to criminal dealings, with Cyrille Le Paradox erasing its contents one Cooper at a time. The gang traveled through time and eventually restored the book to its completeness. Bentley is now caring for the book.
The vault's only entrance is an unbreakable door which can only be unlocked by the Cooper cane. In Sly 3, Dr. M unsuccessfully tries to steal the treasures by breaking open the vault using machine force and by trying to forge the Cooper cane. After many unsuccessful attempts, he grows paranoid and constructs a heavily-guarded fort on it. After recruiting a team of specialist thieves, the Cooper Gang penetrates the defenses around the island and enters the vault.
Inside, Sly Cooper and Carmelita Fox defeat Dr. M, causing the vault to cave in, killing Dr. M. Another entrance to the Cooper Vault was found by Bentley after Sly marked it with his Cane and pouch. After the gang went their separate ways, Bentley and Penelope built a new entrance with upgraded security.
- The circumstances resulting in each of the Coopers' deaths are unknown, though Sly does mention that seeing the silhouette of Clockwerk meant that it was already too late for you, especially if you were a Cooper.