Are Zombies really alive, but everyone assumes they’re dead?

I recently watched a rerun of South Park where Cartman faked Butters death so he could go undercover and discover the secret of the future reading device. While Butters was spending the night at a girl’s slumber party, his parents took the pig body they thought was him and resurrected it like in Pet Sematary by Stephen King. When Butters finally came back home and informed his parents he was in fact alive, they freaked out and believed he was a hideous zombie creature.

This made me wonder, had...