Riddle: Who am I?

Montague took a good look at the Pokémon. It was beautiful, yet really evil and dark, but Montague could tell immediately that it meant no unprovoked harm to anyone. Its gold mask surrounded two bright red eyes that spied the bat watching and quickly shut. It had rings of the precise same gold colour all the way down its back, to about where its stomach would be. That said, thought Montague, I wonder what it eats? Montague thought of the steak he had had earlier, and shoved the thought away. The shadowy Pokémon's body was striped red and black from its neck to its tail, and its snake-like abdomen had silver spikes running down it, tipped with gold. To finish the somewhat terrifying spectacle, it had six tendrils of insubstantial shadow, with menacing red claws attached to the end, that were now curled around the Pokémon for warmth.