A device that defies Gravity.
There are many ways to implement an anti-gravity device, but the most common involves strapping a slice of buttered toast to the back of a cat1)2). The cat must land on its feet, but the toast has to land buttered side down; therefore, the array simply spins in mid-air.
Due to the inherent improbability of Improbable Island, every microwave has a small chance to spontaneously evolve into an anti-gravity device whenever you try to heat up a metal spork3)4).5).
The only current known owner of an anti-gravity device is Johnny Dangerous, who arrived on the island with the device safely hidden up his bum. Unfortunately, no one knows the full tactical advantage such a device provides, as he uses it solely for party tricks and to lift up women's skirts.