It's a Wonderful Knife is an Itchy and Scratchy cartoon in "White Christmas Blues".
In a peaceful town on Christmas, Scratchy runs by a movie theater and says "Merry Christmas movie house!". Then by Itchy's house, whom he says "Merry Christmas, Mr. Mouse!". Itchy pulls on a string of Christmas lights to decapitate Scratchy. He begins to torture Scratchy by using a nutcracker to pull out his eye. At this point, Krusty appears, standing in front of the TV screen and explains that he is blocking violent images in the cartoon because of "modern sensitivity". The cartoon continues with Itchy pulling out Scratchy's eye. Itchy then stabs Scratchy's headless body with a Christmas tree and gut wrenches him. Krusty looks at the cartoon and is shocked by the violence saying "I've never watched one of these sober! I have to get this bloodbath off my kids' show!". He then throws a pie at the TV screen to block all the gore, and the show cuts to a "We'll be right back" message. In the message, Itchy rips out Scratchy's spine and throws it under the word "back", causing a frustrated Krusty to say "Dammit!".
- The title is a reference to the movie "It's a Wonderful Life"
- There's an Itchy and Scratchy comic that has the same name as this episode.