The virus is transformed by bite. It dissolves the victims' skin, makes them lose most complex thinking. It puts them in a state of anger, and hunger for flesh. They grow rows of sharp teeth, and 4 spider-leg like structures out of their back. They become stronger, faster, and more durable, with a slight healing factor. The device has mutated into several variants
The Smasher: This variant grows increasingly strong and large, but slow. They are able to wield large weapons. They become essentially bullet proof, except for their shoulder and neck.
The Cloaked: This variant can become invisible, but leaves thermal signs, and can be heard. They stop being cloaked if attacked.
The Bloated: This variant can spit acid, but is slower, and has a weak spot on their belly which causes them to explode.
The Blinded: The most dangerous variant known. They have no eyes, but can hear insanely well. Small noises, breaths, and fast heartbeats. They can go to 0 to 60 miles an hour in an instant, in short bursts. They use echolocation to move around.
The Grunter: A badly evolved version. This cannon fodder has no tendrils, increased strength, or speed. They are almost mentally braindead. Most of their skin is still kept on their boddies.
There is a rumor of an Apex, the leader. It has every variant's abilities with no downsides, and can even speak. Its existence is theorized, as it apparently cloaks constantly unless he wants to kill a singular target. Nobody who has been attacked by this 'Apex' has survived.