A thus far unnamed ryger male. This one is known as a 'snowcap'.

Snowcaps are similar to common ryger, but are typically darker in color with less visible white. They inhabit the same climate as common ryger, and sometimes are seen with white 'mantles' on their dark bodies. This is actually snow and ice that has frozen into their fur, forming a sort of armor against prey, predators, and each other... The snowcaps posses an even greater tolerance for the cold than their common brethren, and the armor only bothers them when it becomes too heavy for their slender bodies to bear.