Thaddeus Winslow Cooper III is a legendary Cooper Clan thief from Victorian-era London, active around the 19th century. Known as one of the most refined and gentlemanly members of the Cooper family, Thaddeus is a master of disguise, deception, charm, and high-society infiltration. His particular specialty is making himself appear as though he naturally belongs wherever he happens to be, whether among aristocrats, wealthy collectors, guards, or other members of high society.

Thaddeus carries an elegant cane nearly identical to the traditional Cooper cane, distinguished by a ruby-like gemstone embedded in its hooked end. He is highly agile, clever, observant, and capable of turning seemingly impossible situations to his advantage. His talents were recorded in the Thievius Raccoonus under the techniques of “Disguise, Deception and Charm,” skills later used by Sly Cooper to impersonate him and infiltrate a heavily guarded train.

Above all, Thaddeus is a gentleman thief. He is exceptionally courteous, composed, and chivalrous, particularly toward women. His charm is not based on crude seduction or romantic manipulation. Instead, he relies on impeccable manners, confidence, wit, social intelligence, and genuine respect.