Several types of barrels are featured throughout the Sly Cooper series. Some of them are usable by any character to hide from guards and certain types of security systems such as spotlights. They first appeared in Sly Cooper and the Thievius Raccoonus and made appearances in Sly 2: Band of Thieves, also serving as usable items.
They are hollow, cylindrical containers made up of several wooden staves held together by two hoops. They are open at both the top and bottom, which allows the user to jump inside them and walk around. As long as the user is not moving the barrel while in a spotlight or flashlight guard's light, they cannot be seen.
Barrels first appeared in Sly Cooper and the Thievius Raccoonus, where they were first encountered on Raleigh's boat. Here, Sly Cooper had to make use of one in order to reach the treasure key. Sly later made use of another barrel in an attempt to rescue Carmelita Fox from Clockwerk.
In Sly 2: Band of Thieves, barrels were first seen at Rajan's palace, where Sly was able to use them to hide from guards patrolling the guest house. These barrels were also usable by Bentley and Murray if they entered the guest house following "Steal a Tuxedo."
A new type of barrel, the TNT barrel, appeared in the following episode. These were walked around in like normal barrels; however, they exploded once the user jumped out of them. Sly used this barrel type to destroy several laser fences blocking access to Rajan's spice grinder and afterward, to destroy the grinder itself. The Cherry Bomb 500, an especially powerful type of TNT barrel, was used to flood Rajan's temple and draw him out of hiding. Later on, during his infiltration of the RC Combat Club, Murray hid in a barrel while waiting for Sly to steal him a disguise.
Also appearing in Sly 2 were metallic red drums that exploded when struck. These drums reappeared in Sly 3: Honor Among Thieves, both as the standard red variant and as metallic green containers marked with black and yellow stripes. These specially-marked drums, appearing only in one job, had a larger explosion radius.