Yellow Spice

Yellow Spice is a strange spice with magical powers that is named after its color. Early in their history, the Goblins were forced to harvest it by the Kothraki. However, its magic gave them great intelligence and the Goblins overthrew the Kothraki. The Goblins' capital city of Downdelve was likely declared so because it was in the area that contained the vital spice. However, the supply of spice soon ran out. The Goblins searched fruitlessly for more deposits of spice all over the world for thousands of years. Goblin intelligence peaked about 400 years before the Kothraki Invasions of Eredar, and has been declining ever since.