Here are the instructions for creating a head jar to prank your friend.
Start by creating, printing and laminating a cleverly-edited wrap-around portrait of someone’s head (preferably your own). The Instructable has instructions on how to make your own wraparound head photo, but if photo editing is not your specialty, don’t worry – one is available to download in the instructions on Instructables. It need to be fully laminated so that the paper is waterproof. Then, just twist it into a tube and submerge it in a jar full of dyed water. You can even add some herbs or spices to add “flavor” and store the head in a refrigerator to be discovered by an unsuspecting victim. (Source Word For Word: Bored Panda)