The Last of Us

Instead of a mutation of a virus or even a made up element, these zombies are made from a real life fungus called cordyceps. Cordyceps effects insects brains by killing there brain and taking control of their body. Here is a picture:

Cordyceps fungus is a neuroparasite that release airborne spores which attacks and take over the host's nervous system. This causes behavioral changes that allow the spore to spread even more. Eventually the insect will die and fungus will start to grow out of it and release airborne spores.