There are some cases of fungi hijacking insects' bodies and controlling them, so it is definitely possible for a super complex species of fungus to come about and hijack humans. Many of the fungi are actually contagious too, so theoretically, all it would take is one infection to make it an apocalypse.
There is none. But after the many coincidences of zambies in video games, the media, in people's minds... Where did it all come from? There is a possibility of such an outbreak to occur as anything can happen. THere is a type of fungus that actually turns ants into zambies. What are the possibilities of such an occurrence with humans? Just like from "The Last of Us" the chances of a fungus turning humans into zambies is probable. And anything is possible with the new age of technology coming
Zombies don't exist and if they somehow come into existence, they will not last long. A zombie can easily be killed by the strong forces of the army and all that. Any 1 zombie that suddenly appears can be detected and stopped before anything happens. No apocalypse could ever happen.
First off, they're dead! We aren't biologically designed to operate when we are dead. Secondly, they're decomposing so limbs/muscles/everything would just drop and disintegrate. The weather, and the elements won't help either (if anything they will speed up the process). There are also too many firearms, nukes, and military to combat them. The disease prevention units will also seal off the area in a shot. Finally, as a disease it would be very easy to contain. An air born virus is invisible and so are general bacteria &; viruses that we touch on surfaces. An infected zombie is very easy to distinguish from a healthy individual (and transformation is slow but noticeable). Infection can only be passed by biting and scratching but how can you transform into a zombie if a horde eats you pound for pound in flesh & right down to the bone? They are slow as Heck as well. You can easily outpace one by jogging or even a brisk walk. It's worth mentioning even if an apocalyptic scenario does happen in an entire country others would be far more prepared and many ocean based islands won't even be touched from any catastrophic event thousands of miles away. Great Britain for example is only connected to mainland Europe via the channel tunnel and can easily be sealed off. The sea is very adequate protection from the living dead (and even if they continue to be mobile underwater fir some reason, they will surely be destroyed by fish, crabs, and rendered immobile from currents.