Kothraki

The Kothraki, also called The Scourge of Eredar, were evil and sadistic beings, humanoid in appearance, but with a four-tentacled octopus-like head.

The First Kothraki Invasion
For hundreds of years, the Kothraki lived, and presumably thrived, on Kothrak, without disturbing or being disturbed by Eredar. Early in the Second Era, around 385, the Kothraki invaded Eredar, at a time when the Human Empire was still fairly small. This invasion is usually credited with forcing the Dwarven Empire to officially join the Human Empire, under then-Emperor King Ranahaldus. The invaders managed to fight their way through northern Eredar. Ranahaldus eventually defeated the Kothraki, trapping them at Dull Passage and cutting off their supply lines until they died or fled back to Kothrak.

After their defeat, the Human Empire granted amnesty to many of the remaining Kothraki, including taking them on in key political and military roles. The Kothraki presumably bred into the Imperial families, as Kothraki surnames are now considered a thing of pride among Imperial nobility. There are rumored to be small clans of "true" Kothraki still on Eredar, though the details are inconsistent. The military prowess of the Kothraki was one of the key reasons the Human Empire was able to expand as successfully as it did.