Chthonic divinities are associated with the earth and/or underworld. Usually they are fertility gods and/or rulers of the dead, and the opposites of the sky gods. Due to their rather demonic appearance, their cults are usually surrounded with much mystery. Some chthonic gods are for instance: the Egyptian Anubis, the Greek Hades, the Roman Mars, the Etruscan Voltumna, and the Hindu Yakshas.
The word comes from the Greek chtonios, which means "of, in, or under the earth."