The Blue Peacock, a never-deployed Cold War nuclear device, was this type of weapon.
Missile
Bomb
Mine
Anti-tank shell
Mine. The British device was to hold ten 7.2-ton steel casings, each with enough plutonium for a 10-kiloton blast. The strangest aspect of the design called for live chickens to be sealed inside the casing with adequate feed, in order to provide body heat intended to keep circuitry from malfunctioning underground during winter.