Polar dog

This creature is the size of a large dog. It has a pink or reddish nose, rounded ears and three toed paws. Its fur is white except for a black striped pattern that begins at its nose and runs over its forehead and along its back. So far, it has only been seen at the Southern Water Tribe's village. The Polar Bear Dogs are domesticated by the Southern Tribe people and used as pets.

Polar Bear Dogs appeared in "the Boy in the Iceberg."

Connection
The natural connections for this animal are to the real life polar bear, or white bear (though the fictional creature is much smaller), and to the Alaskan Malamutes used in Arctic dog sledding.