a flaming skull

It is a normal humanoid skull, except it is immersed in flames. Through the flames you can see into the black eye sockets and see red, glowing pinpoints. It was once a very knowledgable sage who predicted the downfall of one of Gil-Glash's greatest enemies, who knowing opportunity's unique knock, called the sage to the Grey Keep and made him an advisor. When the sage eventually died of old age, Gil-Glash had a huge ceremony in which he burned several of his slaves on the sage's funeral pyre, which brought the flaming skull to life.