The virus as it turned out had a surprising effect and not what the scientists intended at all. First, to their shock and confusion, it had no effect on animals, which had secretly been the intent of the virus by a few of the group of scientists, hoping that uplifted animals would create a new tidal wave in favor of animal rights.
Second... instead of mutating humans into humanoid normal animal as it was intended... it would transform them into humanoid creatures of myth! With all the tricks and gimmicks that implied! Japanese Kitsune able to shape shift and create illusions. Unicorns were ageless, and could perform any number of feats of magic. Phoenixes able to be reborn for a new life after dying in a burst of flames. Dragons, flying, breathing fire, and acquiring wealth in the most direct and brutal of ways. Gremlins would actively seek out technology and dismantle it. The list went on. The 'best' part (well, not for those changed, most of them) was the instincts... instincts that would drive whoever was changed to act as the creatures of myth were supposed to... keeping all their intelligence and reason... but all directed towards serving the instincts that now drove them.