No, this isn't an animal zombie. But it was.
Shortly before a South American phorid fly larva (not pictured) crawled from this fire ant's
freshly emptied and decapitated head (such as this one in an undated picture), the larva, working from within, had turned the ant into a zombie. Some larvae even compel ants to march to dozens of yards away from their colonies to avoid attack by other fire ants (full story
It all begins with the mother flies. They hover over fire ants, then inject their eggs into the ants with a needle-like appendage.
The egg grows, and the resulting larva generally migrates to the ant's head. The larva lives there for weeks--slurping up the brain (more "zombie" ant pictures
Photograph courtesy Sanford D. Porter, USDA