Ice Demons are a humanoid race of Earthlings that are native to the snow-covered mountains. The race is presumably near extinction, however at least one was still in existence as late as the 1980s, however they were likely at their peak during the Ice Age.
Their physiology is quite unique compared to most Earthlings. They seem to share many similarities to the Icemen, which they could possibly be related to, although this has never been revealed, or even suggested for that matter. The one and only specimen of this race seen seemed to be made of some type of living ice, which means they function best in a cold climate and would not be able to survive any amount of heat. This of course makes perfect sense, due to the fact that the Ice Age is long over and there was only one known specimen. However it is possible that other creatures from this race also exist in colder parts of the world.
They also have very demonic looking horns, similar to that of goats and bulls and other horned animals, however the horns, just like the entirety of the Ice demon's body, is made of ice. The creature's demonic appearance is likely where the name "ice demon" came from. The creature also had what looked like facial hair, such as a mustache and a beard, but these too were made of ice.
They do not seem to possess any human level intelligence, as they seem to act in the manner of wild animals, however, this could just be due to the fact that they are a very violent and reclusive species and it doesn't necessarily mean they are dumb animals. Nevertheless, all things seem to suggest that they are.