Orc and Undead (Definination in Wikipedia)

Orc is a word used to refer to various tough and warlike humanoid creatures in various fantasy settings, particularly in the stories of Middle-earth written by J. R. R. Tolkien and derivative fictions. Orcs are commonly portrayed as misshapen humanoids with brutal, warmongering, sadistic, yet cowardly tendencies. They are variously portrayed as physically stronger or weaker than humans, but always high in numbers. They often ride wolves or wargs.

Undead is the collective name for all types of supernatural entities that are deceased yet behave as if alive. Undead may be spiritual, such as ghosts, or corporeal, such as animated corpses. Undead are featured in the legends of most cultures and in many works of fiction, especially fantasy and horror fiction.Bram Stoker was the first to use the term "The Un-Dead" as the original title for his novel Dracula.[1] Stoker also uses the term in the novel.