America’s greatest living independent animator Don Hertzfeldt (Rejected, Billy’s Balloon, It’s Such a Beautiful Day) is doing the couch gag for tonight’s The Simpsons episode (the one where Krusty’s dad dies).
UPDATE (10/2/2014): And here it is:
On his Facebook page, he advises you to turn the volume way up:
Post by don hertzfeldt.
Hertzfeldt had hinted at the project in his Cartoon Brew]