has been published by several game companies such as Ideal Toy, Milton Bradley, and Hasbro.

[1] The game centers on an articulated plastic model of a mule named "Roo" (or "Buckaroo").

Players take turns placing various items onto the mule's back without causing the mule to buck up on its front legs, throwing off all the accumulated items (the toy has a spring mechanism that is triggered by significant vibration).

The toy has three sensitivity levels that are adjustable via a switch located on the side of the mule's body, under the blanket.

On Good Morning America and CTV News, it was mentioned that an object had hit a child in the eye, in North Carolina, causing the 8-year-old boy to have surgery.