Pillow

The Pillow is a Thing in Paper Mario: Sticker Star. It is the weakest of the sleep-based Things and is found at the Loop Loop River behind a Secret Door. The Secret Door outline is in the room with the Boomerang Bro. It remains in Mario's Album until it is turned into a sticker at a Sling-a-Thing station. Once it has been used as a sticker, it returns to its original position. It may also be purchased from the Shady Toad for 100 coins and sold as a sticker for 20 coins.

As a sticker, the Pillow takes up one square in the Album. When it is used in battle, the background transitions into a silhouetted city at sunset with a pine tree forest nearby. The Pillow lowers and plays a lullaby, causing Mario and the enemies to fall asleep. As it finishes, the screen fades to dark purple and returns to the regular environment. Everyone present in the battle has the Sleep status ailment for three turns afterwards. By pressing repeatedly, the player can attempt to wake up Mario. By getting an Excellent, Mario does not fall asleep and each enemy takes 3 points of damage.

The Pillow can be placed into the Sticker Museum as #50, alongside the other sleep-based and sponge-based Things.

British English Sticker Museum description
"This piece of emergency-response equipment helps the fire brigade rescue people from high buildings. It’s also effective in less stressful situations, like naps."