
A Crocodile Ring
The Crocodile Ring was a ring given the Arthur by Dr. Scamandros, as a means to measure the magical contamination of himself. It was estimated that Once Arthur was 60% contaminated, he would become an immortal Denizen, and lose his humanity. It was shaped like a crocodile curled around in a circle, and split into 10 segments, each representing 10% worth of contamination.
Doctor Scamandros did point out the calibration was unlikely to be totally accurate.
Arthur noted progressive changes occurring as his level of sorcerous contamination grew, and after he used a Key to regenerate a severe brain injury, and presumably completed his transformation, the ring not only turned completely gold, but alternated between rose and normal gold, possibly hinting at Arthur's special status.