|Picture from Paranormal Animals of Europe|
The Protean (Entamoeba imitatrix) is believed to be the Awakened form of the amoeba that causes human dysentery (Entamoeba histolytica) that somehow encorporated the Boltzmann-Schneider virus into its cellular makeup. It is an amorphous mass, a collective aggregate of individual protozoan cells weighing between the wide range of 0.5 kilograms to 125 kilograms.
This carnivorous mass hunts by concealing or disguising itself into the form of a creature it has most recently eaten. It engulf its prey, killing it with corrosive secretions. Very few measures can destroy a Protean, including fire, alkaline chemicals, and hydrophobic substances.
Professor Andreas Szerinsky at Moscow University postulates that the Boltzmann-Schneider virus somehow allows the Protean to decode and imitate an engulfed organism's "metamorphogenetic field", and that a sufficiently high electromagnetic field fluctuation would disrupt the Protean.