Reindeer are the largest deer species in the world, with males growing up to 6 feet in height and weighing as much as 600 pounds. Female reindeer are smaller, with an average height of 4 feet and weight of 300 pounds. Reindeer have thick coats of fur that protect them from the harsh climate of the Arctic, and their antlers grow up to 3 feet long. The species is known for its endurance and adaptability, being able to survive in both extreme heat and extreme cold.