Frankly, the cyborg zombie beetles of Professor Mahrabiz seem more undead than Twilight vampires. Decaying zombies are probably undead, and Harry Potter Inferi are definitely undead, as are Dungeons and Dragons undead (where the vitalistic dualism is very explicit.)
Could you then give an example of what you would accept as a legitimate undead creature?
That’s… actually complicated.
Frankly, the cyborg zombie beetles of Professor Mahrabiz seem more undead than Twilight vampires. Decaying zombies are probably undead, and Harry Potter Inferi are definitely undead, as are Dungeons and Dragons undead (where the vitalistic dualism is very explicit.)