They are categorized as a species, but since they are monsters that have come back to life, they aren't technically a species. Because of their smell, they're generally hated, but they do have a cult following. Most undead are weak, but those of the King variety are known to be as strong as an overlord.
☆ Episode VII (Salamander's Breath)
Disgaea: Hour of Darkness Wiki thrives to be mobile-friendly!