The Thief Costume is a costume available for Sly Cooper in Sly Cooper: Thieves in Time that "is rumored to be the outfit of a real genie." It formerly belonged to Salim al-Kupar, but was lost in a bet on a camel race. Sly had to get the outfit back so he could gain Salim's trust that the Cooper Gang are trying to help him. He had to steal three priceless gemstones and give them to a snooty salesman that would not leave his post.
The Thief Costume is made up of several parts. There is a red bandana atop Sly's head, along with two gold earrings on his left ear. He also now has a black goatee. The shirt is white with gold lining around the collar and down the front of the shirt, as well as gold cuffs. Over the shirt is a blue vest that has a gold badge or medal and frills on the bottom. Around Sly's waist is a red scarf-like belt. He also wears blue pants and red genie shoes. On his back is a large scimitar, and in his hand is an hour-glass topped wooden staff.
The costume makes use of two functions; the first being the hourglass staff that gives Sly the ability to slow down time without slowing down himself, the second being a powerful scimitar that Sly can use to destroy objects, specifically chains and gears.
The staff that replaces Sly's cane does not have a hook so the ability to hook and swing is removed.
- According to concept art, the costume's sword was originally going to be used to open unique locks instead of cutting metal chains.
- It can be used to slow down the countdown when trying to collect treasure, making it easier to collect it.
- The Thief Costume can be very helpful on missions when replaying them to get the Sly masks, It can also be used to catch the train in Episode 2.
- The Thief Costume is also available as an alternate skin for Sly in PlayStation All-Stars Battle Royale.
- This costume, along with the Archer Costume are the only two costumes that retain Sly's acrobatic mobility.