![Zombie](https://cdn.pixabay.com/photo/2015/10/12/14/58/hands-984032_960_720.jpg)

Zombies had always been a topic of special interest for Professor Smith. For years, he had done research on different parasites that affected animals. He couldn’t help but wonder what would happen if one of these parasites one day decided that humans were their preferred host after all.

His lectures had always been full, but people didn’t really take him seriously. He had offered his research to the military, but all he got were calls from writers who needed new ideas for movies and video games. He never wasted his time with them.
In the end, he realized that he needed to deliver proof of his theories, or else nobody would ever believe him.

It had become clear pretty soon that a complicated organism like a human would need more than one parasite to make them into a good, usable zombie. And the combination shouldn’t be too deadly, because that would just make the creation useless.

Nature was full of pretty deadly parasites that turn their hosts into zombie-like creatures. The probably most famous ones were the fungus Ophiocordyceps, which hijacked the central nervous system of ants and made them climb up leaves, and the flatworm Leucochloridium paradoxum, which forced snails bring themselves into situation where birds could eat them more easily.

But both of these parasites were utterly useless for Smith’s goals. He didn’t want to change one single kind of behavior and then kill the host. He needed to change a human being into a half-dead killing machine that followed orders.

For some time, Smith had done some experiments with the venom of the emerald cockroach wasp. The unique mix of neurotransmitters this insect produced was able to render a cockroach totally passive even when it was eaten alive. But that kind behavior was more useful in a victim than in a soldier.

He had finally decided to work with those parasites that were already known to cause changes in humans they infected. Toxoplasma gondii, a single cell organism that originally caused mice and rats to lose their fear of cats, had long been suspected to induce personality changes. It had been relatively easy for Professor Smith to infect some of his students to test if it would actually change anything.

After a short period of time, he had been able to observe that the students he treated with Toxoplasma became more extroverted but also more aggressive towards their peers.

Satisfied, Smith had continued to carefully craft his zombification drug.

The final result was a piece of art. Toxoplasma got company from the Rabies virus, which caused an even higher aggression and made it difficult to swallow, inducing an always growing hunger. To direct this hunger, Smith added the nectar of the acacia tree. This nectar possessed the ability to change the biochemistry of the patient in a way that made it impossible to digest anything but the nectar itself. 

Professor Smith was proud of himself. It wasn’t quite the kind of rotting zombie the media liked to portray, but in his eyes, his invention was better. Those who got infected by his drug would kill whoever their superior pointed at, without question, without remorse, without mercy. And they would never turn against their master, because without the precious nectar, they wouldn’t be able to survive.

The vial with the zombie drug was carefully placed in Professor Smith’s briefcase. He wondered which of his students would be the one he’d present to the military as the first perfect soldier.

*Footnote: While this is a fictional story, the parasites mentioned do actually exist. And they're not the only ones.*

*Sources + Read more:
https://www.livescience.com/47751-zombie-fungus-picky-about-ant-brains.html
https://parasiteecology.wordpress.com/2013/03/18/zombie-snails/
http://animaldiversity.org/accounts/Leucochloridium_paradoxum/
http://mentalfloss.com/article/56018/8-parasites-create-zombie-animals
http://www.bbc.com/earth/story/20150316-ten-parasites-that-control-minds
http://rspb.royalsocietypublishing.org/content/273/1602/2749 (Effect of Toxoplasma gondii on humans)*

Picture taken from pixabay.com