Aurorus is the Tumdra Pokémon from the sixth generation of the franchise. It evolves from Amaura at Level 39 when leveled up at night.
In the Pokémon games
Aurorus has only appeared in two Pokémon generations, the sixth one, and the seventh one. It cannot be caught in the wild, making it obligatory to evolve Amaura or trade.
Aurorus can only be obtained in game in Ultra Sun and Moon, so it must be traded into Sun and Moon
In the competitive Pokémon scene, Aurorus is bottom tier due to its appalling type combination and low speed.
In the Pokémon anime
Aurorus and its pre-evolution Amaura were both in the episode Coming Back into the Cold!, they were both revived after being frozen in ice.