The Fart in a Jar is an accessory that allows the player to perform double jumps by hitting the jump key again in mid-air. Although it is crafted with a Cloud in a Bottle, it jumps as high as a Blizzard in a Bottle. It creates a cloud effect while ascending with it, and can be combined with the Shiny Red Balloon at the Tinkerer's Workshop to make the Fart in a Balloon. It will also play a fart noise, as the Whoopie Cushion allows. It has a slightly green cloud, unlike the Cloud in a Bottle, which produces a white cloud.
- If the player has the Spectre Boots/Hermes Boots/Flurry Boots or any other kind of boots that allow them to run fast, using the Fart in a Jar will allow them to instantly run fast instead of building up speed.
- Became an ingredient in Fart in a Balloon.
- Added to the game.