Hare (Franchise)

The Hare is a small mammal mentioned in the game, School of Dragons

Description
Hares (Genus Lepus)are closely related to rabbits and are often confused with them. Generally, hares have longer ears and legs than rabbits, but not exclusively. The young of the hare are also born with open eyes and fur, which contrasts with rabbits. Rabbit babies start out with unopened eyes and no fur.

The Arctic Hare is mentioned specifically in School of Dragons. This hare lives in the tundra of North America (but not Scandinavia). They eat whatever plant life exists in their environment, along with lichens, mosses, and seaweed. Occasionally they may eat Fish or the entrails of Caribou, which would contain partially digested plant matter.

Function
Thus far in the How to Train Your Dragon Franchise, hares have no function other than as a nuisance animal that eats crops. It might be presumed that they are also eaten by humans as in real life, and by extension, dragons.

School of Dragons
Arctic Hares are mentioned in the Icestorm Island Expansion Quest, "Dirty Rotten Thieves". Mildew blames dragons of eating his Cabbage garden. The player must find evidence by following the tracks around his garden. The player finds an arctic hare is the culprit.

How to Train Your Dragon (game)
One of the characters seen in this game is named Harelegs.