Cryptozooglogists, Necrologists, and Zombologists classify zombies as Homo Necrosis Zombifis under the supernatural sciences. The complete paranormal classification is below:
Kingdom: Cryptida (Supernatural Cryptids)
Phylum: Immortalis (Immortals)
Class: SupraNecrosis (Living Dead Beings)
Order: Magica (A Product Of Magic)
Family: Anthropophagis Sanguinus (Survives Off Human Flesh And Blood)
Genus: Homo Necrosis (The Melding Of Human And Zombie)
Species: Homo Necrosis Zombifis (Scientific Name For Zombies)
Cryptida is the seventh Kingdom that mainstream science refuses to acknowledge.
Despite Zombies being technically Immortal they also are in a state of rotting necrosis which means they will be non-animated in less than a decade depending on the circumstances of the environment they menace. However magical intervention could theoretically extend their destructive lives indefinitely. The original supernatural zombie virus is a product of a magical accident. In addition to practitioners of magic raising corpses from the dead the zombies themselves can pass on the virus to make new zombies.