A half-god is the offspring of a human and a god.
Examples of half-gods In Billy and Mandy[]
Nergal Jr. (human mother, god father)
Appearance[]
Since Nergal Jr has a true form that is separate from his human form, it can be assumed that half-gods are a combination of both their parents.
Trivia[]
In folklore, the offspring of a human and a god is called a demigod, though that term isn’t used in the series.