Ah, reader, you may request as many pokémon as you wish!
Amaura
The Tundra Pokémon
Type: Rock/Ice
Official Registration #: 698
Entry: This gentle pokémon lived in the northernmost regions of the planet roughly 100 million years ago. However, evidence shows that amaura actually originated from warmer climates and migrated northward due to encroaching tyrunt and tyrantrum over a period of millennia. The gradual movement of these pokémon allowed it to adapt to colder weather and develop both its affinity with the ice element and its ability to use officially normal-type moves as if they were of the ice type instead. And we know all of this partly due to the skills developed by paleontologists over the past couple of centuries and partly because certain inventors have taken to reviving amaura from fossils alongside its only predator as if there is absolutely nothing wrong with that idea.
Aurorus
The Tundra Pokémon
Type: Rock/Ice
Official Registration #: 699
Entry: The evolved form of amaura, at night and by battle experience. Aurorus has apparently gained every adaptation possible for defending itself from its tyrantrum predators. Not only has it become adept at using ice-type moves (including those it improvises as being ice-type), but it is also capable of forging a wall of unbreakable ice, breathing gusts of air that reach temperatures of -240 degrees Fahrenheit, and, if all else fails, bringing attention to itself by projecting auras into the sky. Why might that last adaptation be its last resort, you ask? Because aurorus have been known to travel in large herds, and every individual aurorus is on average 496 pounds. Factor in the fact that tyrantrum were not known for hunting in packs, and you have possibly the most effective predatory deterrent short of any water-type pokémon using wailord as a shield.
The Pokédex According to Bill 