Check out this production art from the Satan vs. ManBearPig fight.
Al Gore is still sporting his bowling shoes. Check it out.
Satan got a character update during season 18. Check out the new design
Check out his production art of Satan with his halo and angel wings.
You can see the stages of production for this shot. First storyboards, then art design.
Check out this art of ManBearPig in a suit.