Doom Diver Catapult

A Doom Diver Catapult is basically an enlarged version of a giant slingshot, which propels a leather-wing Goblin known as Doom Diver straight into an enemy formation as a form of live ammunition. Originally, the Doom Diver Catapult was created to allow nomadic tribes of Goblins to scout the surrounding areas of their territory in quick succession. After a while, the Doom Diver Catapult was redesigned for the use of war.

When a Doom Diver Catapult is brought into battle, a crew of Goblins would begin to pull upon the sinew while a Doom Diver is adjusting himself upon the catapult. Doom Divers are quite enthusiastic about their duties, for there can be no greater joy for a Doom Diver than to fly across the sky for only mere moments before he hits his intended target. Though it is a sad way for a Goblin to go, it is infinitely more better than to die an ignoble death by the hands of a hungry Troll.

The height a Doom Diver can reach is dependent upon the quality of his wings, how far his crew can pull the sinew back as well as several other factors. Sometimes the over-anxious Doom Diver gets his elastic strings tied up in knots and would take some time for him to untangle. Other times, the Doom Diver miscalculates and is instead shot to the ground right in front of him, killing him instantly. The worst that could happen is when the crew manages to accidentally snap the sinew, which would kill the Doom Diver and destroy the Catapult itself.

On those successful occasion when a Doom Diver crew is ready to fire, the sinew is stretched back to the limits of the crews strength until they let go and shoot the Doom Diver into the air. Ripping skyward like a bullet, the Doom Diver often reaches cloud level before he would begin is slowly escalating dive. Using his wings, the Doom Diver would spiral and guide himself towards his chosen target, emitting a loud and high-pitch scream just moments before making impact. The outcome usually ends in the death of the Doom Diver, and hopefully his intended target as well. Some of the smarter or more experienced Doom Divers would apply his wings effectively as brakes and if he is lucky enough, he might bounce from the impact instead of splatter into the ground. As such, there is still a few veteran Goblins whom have lived through their experience as Doom Divers, only to willingly re-live this experience one more time.

Source

 * Warhammer Armies: Orcs and Goblins (8th Edition) -- pg. 48