The Gnolls of the Trackless Plains are a terror that makes caravaning across the plains to the great cities of the Southwest difficult at best, and often deadly.
Gnolls are the spawn of Yeenogu, a demon prince of the abyss who thrives on savagery and slaughter. It is said they come from hyenas that followed the Lord of Savagery on a rampage, and ate the corpses left behind. When they rested, they transformed into Hyena/Demon hybrids in a shower of pain and gore.
They are always hungry, and only the flesh of intelligent creatures satisfies their hunger. Strength, hunger, and fear are their three major concepts: Strength to overcome foes, hunger motivates the gnoll to go forth and slay, fear is a weapon used to make enemies easy prey.
They cannot be negotiated with, their only object is to slay all other creatures, until all are dead. Once all the other beings are gone, the gnolls will turn on each other until only one is left. Then Yeenogu will come, kill the champion, and rule over a material plan full of corpses.
The Fangs of Yeenoghu are gifted with the power to create more gnolls by anointing the remains of their foes. When the corpses are eaten by hyenas, the hyenas become gnolls. Sometimes other humanoids are forced to partake in the feast, they become crazed cultists.
Even death cannot dissuade the gnolls, as their leaders can raise the corpses of killed gnolls as undead Witherlings.
They are a plague upon the plains, and are kept in check by the efforts of Elven Rangers and other guardians of the forest, to keep the route east and west clear. The Wolf Axe band of Orcs of the plains also war with the gnolls.