The Ghoul is among the most unfortunate of the denizens of Sidereus. Commonly known for their grave-robbing behaviors and their diseased appearance, Ghouls are among the ranks of the "unliving". Distinguishable from the undead because they are not truly undead. In fact Ghouls experience a sort of half-life, where they are forced to eat and do many of the other things that living creatures can do (including procreate), but their bodies are warped versions of the Human form as a result of an insidious and ancient Necromantic plague.

Ghouls are not able to eat in the same fashion as a healthy, living Human being. Instead they are relegated to surviving on consuming the flesh of recently dead humanoids. In some cases, they are able to consume the flesh of the living, but this will often cause them to become ill and contract a Ghoul-specific disease that is very similar to rabies in its manifestation.

While Ghouls are able to birth offspring, the process is extraordinarily painful and beyond grotesque. Many Ghouls are stillborn as the Necromantic taint in their blood is simply too much for the gift of Life to surpass in some cases. When there is a failed birth, the family of the stillborn child will often consume it in what has become a form of ritualized cannibalism.

The Necromantic taint that has caused Ghouls to become what they are is contagious, though becoming infected with the disease usually requires prolonged physical contact or something more intimate such as a bite or a kiss. Ghouls commonly reek of death and decay, and as a result they are particularly easy to track by scent.

Despite their significantly negative social status, Ghouls are not inherently hostile. They are often very passive, and can be peaceful in many cases. Ghouls will often become scavengers, trading the goods they are able to salvage for money or food. Some less judgmental societies will work with Ghoul encampments, since they can essentially trade refuse and garbage for useful items and equipment.

It is rumored that there is a breed of Ghoul that has emerged as a result of Wyld magics, though these Ghouls are more bestial and far more willing to attack anyone who crosses their path. They are also rumored to have yellow skin.