In "I Know What You Did Next Xmas", Professor Farnsworth goes back in time to attempt to fix Santa's naughty and nice sensor. When he believes he did so, he has everyone celebrate Xmas with their families, however, Bender and Zoidberg have no families to go home to, so they go back in time to murder Robot Santa. They do their best to hide the body all around, but by the end, they see that Santa is still alive and still thinks everyone is naughty, because the Professor created a paradox in which he was the one who made Santa think everyone on Earth was naughty.