Giant

Giants tag along with greenskin hordes for the oldest bargain in the Old World: food. A warboss with a stolen herd of cattle and a wagon of ale can buy the loyalty of a creature tall enough to peer over castle walls, and no greenskin has ever considered the price anything but a steal. The giant gets fed; the Waaagh! gets a siege engine with a hangover.

In battle a giant is less a soldier than a weather event. It swings clubs the size of ships' masts, stuffs screaming knights into its sack or straight into its mouth, headbutts things that were built to withstand battering rams, and occasionally (gloriously, catastrophically) loses its balance. Whole regiments have been ended by a giant's fall. On this much, at least, greenskins and their enemies agree: you keep an eye on the giant, whichever side it is on.