Polar bear the polar bear in advertising, while Fox's Glacier Mints have featured a polar bear named Peppy as the brand mascot since 1922. Polar bears are popular in fiction, particularly in books for children or teenagers. For example, "The Polar Bear Son" is adapted from a traditional Inuit tale. The animated television series "Noah's Island" features a polar bear named Noah as the protagonist. Polar bears feature prominently in "East" (also released as "North Child") by Edith Pattou, "The Bear" by Raymond Briggs (adapted into an animated short in 1998), and Chris d'Lacey's "The Fire Within" series. The "panserbjørne" of Philip
Polar bear frequent and recent mating. Polar bears can breed with brown bears to produce fertile grizzly–polar bear hybrids, rather than indicating that they have only recently diverged, the new evidence suggests more frequent mating has continued over a longer period of time, and thus the two bears remain genetically similar. However, because neither species can survive long in the other's ecological niche, and because they have different morphology, metabolism, social and feeding behaviours, and other phenotypic characteristics, the two bears are generally classified as separate species. When the polar bear was originally documented, two subspecies were identified: "Ursus maritimus maritimus" by