Sweepers are Blotlings that largely resemble the Brooms from Fantasia. They carry buckets of thinner to throw at you, and will sweep you away if you get too close. They can be befriended by Paint and be destroyed by Thinner. You first meet them in the Jungle Boat ride. They are part of the Shadow Blot's Blotling Army.
As seen in the picture, using a TV will distract them. They'll use their thinner buckets as a seat and watch intensly. Hitting them with anything (Paint, Thinner, Swing attack) will break them out of the trance and start attacking you again or go back to watching if you painted it.
Even after you have redeemed it with paint the Sweeper will still throw Thinner to attack Enemies so it's a good idea to redeem it where there is no toon floor as it may unintentionally thin the floor out while fighting. This can also cause problems if the player is painting another Blotling. The Sweeper's thinner attacks will partially undo the players paint, making it much harder to befriend enemies. This is especially true during the final wave of Blotlings inside the Blot, making it a tough battle for Hero players.