Polar bear

Polar bears were a type of bear typified by their all-white pelts, and their proclivity for living in cold climates. During a mission for Santa Claus in snowy conditions, the First Doctor encountered and was menaced by a polar bear. He was rescued by John and Gillian, who used the Doctor's "magic box" to miniaturise the bear. (TVC: A Christmas Story)

As the Eleventh Doctor attempted to use the Visual Recognition System to determine the species of a drawing of a Krafayis, it offered a polar bear as one of the incorrect identifications. (DW: Vincent and the Doctor)

A mounted polar bear was one of the exhibits in the National Museum. (DW: The Big Bang)