Costumes are alternate clothing for Sly Cooper in Sly Cooper: Thieves in Time. Despite being similar to the disguises from Sly 3: Honor Among Thieves, only the Samurai Costume and Sabertooth Costume can be used as a disguise; none of the other costumes can fool the guards of the episode. Rather, their main function are their unique abilities, such as the Samurai Costume which can protect Sly from fire. Newly obtained costumes can help the player reach new locations in levels previously visited.
Samurai Costume - obtained by pickpocketing the guards. In Turning Japanese it is used to pass the guards but its overall use is to deflect fireballs from El Jefe and the dragon doors in each episode.
Jailbird Costume - obtained after Sly is placed in jail in Go West Young Raccoon. Can be used to push heavy cages that have glowing red lights on the side as well as the Atlas doors in each episode. Secondary use: Rolling wrecking ball.
Sabertooth Costume - obtained after Sly sneaks into Grizz's hideout and finds an unlikely discovery in Clan of the Cave Raccoon. Main use is to play dead and use the Cyclone Pounce to leap long distances by attacking guards or stuffed mammoth standees.
Archer Costume - obtained after gathering the materials for the bow and arrows in Of Mice and Mechs. Can use all of Sly's moves except the stealth finisher ThiefNet power-ups. Mainly used to hit targets to create tight ropes, bull's eyes give you coins. Can also be used to attack enemies and do recon.
Thief Costume - obtained after saving Sly's last ancestor and obtaining the three flawless rubies in 40 Thieves. Similar to the Archer Costume in the sense that it can use all of Sly's moves expect the ones listed in Archer Costume. Main use: Time Manipulation, slows time down to climbs brittle chains and poles with snake baskets under them. Also used to keep hourglass doors open long enough to enter. Secondary use: Sword attack.