Ophiocordyceps unilateralis is an entomopathogen, or insect-pathogenising fungus, discovered by the British naturalist Alfred Russel Wallace in 1859, and currently found predominantly in tropical forest ecosystems. O. unilateralis, also referred to as a zombie fungus, infects ants of the Camponotini tribe, with the full pathogenesis being characterized by alteration of the behavioral patterns of the infected ant.
@ https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis
Leucochloridium paradoxum, common name green-banded broodsac, is a parasitic flatworm (or “helminth“) that uses gastropods as an intermediate host. It is typically found in Succinea that live in Europe and North America where it infects the host’s eyes making them appear as caterpillars that other birds prey on. Various birds consume these infected gastropods, becoming the definitive host for L. paradoxum to mature and release eggs in the rectum that are later found in the feces of the bird host.
@ https://en.wikipedia.org/wiki/Leucochloridium_paradoxum
For more:
@ http://news.nationalgeographic.com/news/2014/10/141031-zombies-parasites-animals-science-halloween/
Quisquilie & Pinzillacchere 