Mary was the mother of 3 teenage triplets. they were fraternal of course. there was Alex who was currently in his room playing on his phone. then there was Sally a beautiful young woman currently painting her toenails. there then was her final child Max, who was the brains of the family and was currently reading a book in the study. her husband Harry was currently at his job as a construction worker. Mary herself was currently putting away groceries.
what none of them realized was that the secret evil cooperation had altered the virus. the virus still mutates the victims, however, these changes will always have some kind of animal change to them. theses changes can be part or all of the body becoming that of an animal, even if the animal part doesn't match with the person's body. for example, a person may have their feet replaced with lion heads or a person's head replaced with a dog's butt.
there is also the chance that a person will become an anthro, even going as far as changing gender. the changes don't just be confined to one animal. a person can have multiple animal parts to them. a woman might find her waist becoming squid's lower tentacles while her hands become bird wings and grow an ape head beside her own. the victim if in contact with any animal will find themselves merging with that animal. two men could merge with a bull and become a two-sided female cow.
of course, the first victim of this new strain would be the Marshfield family. but the question would be who?