"'Twas the Nut Before Christmas" is the fourth Christmas episode of the animated sitcom King of the Hill, aired in the show's fifth season.
It's Christmas time and Bill feels lonely and jealous of his friends because he has no children of his own to buy presents for, so they decide to enlist him in a program buying presents for poor children who wrote letters to Santa and he is disappointed that the person who delivers the presents isn't going to be dressed as Santa so he gets the idea to have his own Santa shindig to make children happy everything goes fine for a while and he even gets a date with a single mother and her two children.
Soon New Year's Eve arrives and Bill wants to keep being Santa because he just got a new jump house and the children really like it, Bill ends up wearing the Santa suit everywhere and it gets covered in crumbs and stains. When he washes it, it shrinks and turns pink and soon the children stop coming, the woman arrives for Valentine's Day but is disgusted with him because he's still wearing the now tattered, shrunken, and pink Santa suit and leaves him.
Bill runs into a man named Wally whom Bill takes in as a son after he loans him some money, Wally turns out to be a bad influence as he parties every night and steals things, it's the final straw for Hank when Wally gives his son Bobby and his friends beer, Wally is later arrested for stealing a truck and Bill is worried about him, later in court Bill convinces him to join the army rather than stay in jail and finally stops wearing the Santa suit.