Scott Wills has done some great backgrounds on cartoons from the past couple decades, including Ren and Stimpy, Samurai Jack, and Clone Wars. Check out more of his work here CandyCaneLand.
Something interesting happens during the last two backgrounds, they play out in one continuous scene, but when Daffy reaches the corner of the wall and cieling, the details of the background don't quite match up to the previous frame, which leads me to believe they are two separate backgrounds.