Mr. Hankey is a sentient, jolly piece of feces and the former Christmas deity of South Park, taking the place of others, such as Frosty or Rudolph. On Christmas, he comes to visit those who has a lot of high fiber in their diets. Prior to being relocated to the town of Springfield from The Simpsons, Mr. Hankey resided in the sewers beneath South Park, and therefore has been known to appear as if by magic from out of toilet cisterns, bringing with him tidings of joy, and a ghastly smell. He first appears in the Season One episode 'Mr. Hankey, the Christmas Poo'. (Source: Fandom.com, CC BY-SA)