The Beastmen are grotesque hybrids of humans and beasts that embrace Chaos willingly and seek to end the world in bloody carnage. They are a new, more difficult Enemy faction added by the Winds of Magic DLC.
Beastmen are a race of savage mutant humanoids that bear various traits of bestial appearance, such as cloven hooves, muscular human bodies and horned bestial heads. Their status in society corresponds to the colour of their hide and horn size, where the beastmen with smaller horns are lowly as well as their full size.
Because of their more primeval nature, most beastmen do not seem to use any advanced technology, resulting in them only using very basic weapons like spears and axes. Even higher in the hierarchy they seem to not use anything mechanical, unlike the skaven.
Beastmen follow a violent hierarchy based upon the overall prowess of a Beastman as well as what kind of breed the particular Beastman is. Those Beastmen that possess small horns or none at all, such as the lowly breeds of Ungors and Brays, are always below those that do such as the Gors and Minotaurs.
The following Beastmen units appear in-game:
For more in-depth lore, vist the Warhammer Fantasy entry on Beastmen