The Ice Cave Hopper

      Unique in the world, and certainly within its home range of the Coast of Antarctica, the Ice Cave Hopper is classified by most pseudo para-biologists as the last surviving advanced pre-mammalian (or therapsid) synapsid.  As a therapsid it is endothermic; as a creature that has evolved to live in one of the singularly most extreme environments on the planet, it also has a unique sub-cutaneous fat layer and extremely thick skin, with few blood vessels near to the surface.  It is also the only surviving advanced terrestrial life form on Antarctica, other than the penguins,  from the period some 15 million years ago when Antarctica still had tundra and even coastal beech forests. 
       The Ice Cave Hopper spends over 95% of its time in the shelter of its eponymous subterranean environment.  When the Ice Cave Hopper does venture out into the Antarctic open air, it is usually to scavenge the dead and dying from massive penguin colonies.  Rarely does the Ice Cave Hopper risk expending precious energy on actively hunting healthy prey, even of the smaller penguin species.  With sharp bony ridges in place of regular teeth, Troglodytarum-Canis Hyacintho is well adapted to crushing not only the light weight bones of its regular avian food source, but also to extracting all available nutrition from the occasional windfall of much more robust pinniped or even cetacean carcasses on the beaches.
        Averaging two feet in length from its over sized head to the tip of its tail, and approximately 12 inches at the shoulder, the Ice Cave Hopper was described by the Australian adventurer and "rosea elephantem vanis" Harold Rooker as "a Tasmanian devil on valium, but with the hopping ability of a tree kangaroo with arthritis."  Weighing between twelve to fifteen pounds, Troglodytarum-Canis has no known surviving regular predators, other than the occasional leopard seal taking a juvenile that strays too close to the waters edge; however, cubs, which are born live with up to six siblings with approximately one litter every two years, may occasionally fall prey to the feral cats on Macquarie and Marrion Islands off the Antarctic Coast.