Rangifer tarandus

The reindeer (Rangifer tarandus), also known as the caribou in North America, is a species of deer native to Arctic and Subarctic regions.Reindeer vary considerably in colour and size. Both sexes grow antlers, though they are typically larger in males.
Reindeer are ruminants, having a four-chambered stomach. They eat lichens, reindeer moss, the leaves of willows and birches, as well as sedges and grasses.
Except in December when they favour carrots and mince pies.