Grimm

"For as long as humanity can recall walking the surface of Remnant, so do they remember this wicked force. The Grimm are so evil that they could destroy us all. But how can this happen? Seriously?"

--Su Ji-Hoon, World of Remnant

Grimm, or the Creatures of Grimm, are the universal antagonists of RWBY, inhabiting various parts of Remnant.