- "Did you hear the one about the Hippogriff and the Saddle? You wouldn't get it..." -The Killing Joke
The Killing Joke is a powerful incantation taught to JimJam by Death Himself in Episode 12, Season 2 of the Landscape. As the name implies, the Killing Joke snuffs the life from those that are unlucky enough to be listening (as seen in Episode 15, Season 2).
Unlike the majoirty of JimJam's famous verbal assaults, and despite its name, the spell cannot be considered a real joke, since it lacks a distinct punch line. However, the brief, nonsensical phrase begins harmlessly enough that its listeners have little time to ponder the phrase's comicality - or lack thereof - before they are killed instantly. Although the Killing Joke supposedly kills all within earshot, JimJam was somehow able to be told the Killing Joke and live, possibly because according to Death Himself, JimJam has "No Expiry Date."
The Killing Joke was created by Death Himself, which some say may account for its complete lack of humor.