Fortunately for humanity, even on Halloween the zombie menace is still basically a fictional threat.
But a look to the animal kingdom might make you think twice.
The natural world is rife with fungi, parasites and insects that survive using many of the same tactics as our fictitious undead enemies, including feasting on the brains of their prey and infecting and reanimating the all-but dead.
From the Cordyceps unilateralis, a fungus that infects ants with spores before controlling its movements, infecting other ants and then exploding through the poor host's head, to the slightly more subtle 'zombie worms' that devour dead whales, there is a horde of zombie-like beasties out there to inspire Hollywood for years.
There are even one or two zombie-likes that might pose a threat to humanity after all...
See our gallery below for the creepiest and scariest real-life zombies that nature has to offer.