It seems the magical nature of the creatures exoskeleton is a means if disguise. It was discovered more by accident than purpose. In the last week we had discovered only that it was imbedded with some sort of illusion spell. As we prepared to dissect the creature an assistant brushed a hoof across it and the creature became a perfect copy.
Weather this is some cadaveric reaction or I mistook the creature for dead I do not know. It is currently locked away in isolation as we wait to see if there is any lasting effect of the transformation.
Well placed members of the castle staff, guard, and denizens of Canterlot proper have been informed to look for suspicious behavior. These creatures may be able to take on another’s appearance but there is much more to each one of my subjects than the color of their tail.
-L