There was an arthur episode where arthur, francine, the brain, and i think buster play with transformers toys in the sandbox and the brain had one that transformed into a washing machine. not sure what it was called
www.cartoonnetwork.com/promos/201004_fda/flashpage.html Not sure what year these were from, but I do remember them being in between Adventure Time episodes if that gives you any point of reference. I'd say maybe 2011 or 2012? Not sure. Anyways, here you go!