World War Parasite

A meteor has struck Earth bringing deadly parasites that resemble snakes that take living things at hosts. Once it has its host it with most with other of its host’s kind to get more parasite-infected creatures once that is door the mate will also be infected. It mostly happens in cows, and when cows and everything other creature is infected, they get abnormal behaviour like there heads falling off, limbs being the wrong way and necks extending ridiculously large.