Santa Claus rides in his sleigh as he prepares for Christmas in the Arctic Circle near Rovaniemi, Finland December 15, 2016. At Santa Claus' Lapland home in Finland, his helpers sort out piles of letters from around the world, each detailing children's requests for this Christmas. (Photo by Pawel Kopczynski/Reuters)

The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg (31 and 99 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Although it can walk on land, the sea otter lives mostly in the ocean.

This undated photo shows the Arctic National Wildlife Refuge in Alaska. (Photo by U.S. Fish and Wildlife Service/Getty Images)

The waning moon sets behind leafless sumac trees on a crisp, clear morning, Thursday, December 15, 2016, in Portland, Maine. Much of the northern Mid-Atlantic and Northeast will stay cold for the next couple of days as the arctic air remains stuck over the northern Appalachians, the National Weather Service said. (Photo by Robert F. Bukaty/AP Photo)

A tourist takes photos of an Aurora Borealis display (Northern Lights) over the Bals-Fiord north of the Arctic Circle, near the village of Mestervik late September 30, 2014. (Photo by Yannis Behrakis/Reuters)

Northern lights (Aurora borealis) glow brightly over an Inupiaq fish camp along the arctic coast in North Slope, Alaska. (Photo by Steven Kazlowski/Barcroft Media)

The northern lights, or aurora borealis, illuminate the sky over Flakstad beach on Lofoten Islands in the Arctic Circle on September 5, 2017. (Photo by Jonathan Nackstrand/AFP Photo)

The stunning shots capture the moment a female bear and her two cubs enjoyed the last warm rays of the sun at the Arctic National Wildlife Refuge in Kaktovik, Alaska. The bears can be seen gazing at the vibrant sunset and appear to revel in the tranquil moment as they bask in the array of colors. (Photo by Sylvain Cordier/Caters News)