Oleum is a fakemon of mine that happens to adore the sunset because it looks like the sky catches on fire.

Oleum, the oil slick pokemon
fire/water type
Oil is collected on its back over time and can be ignited at will by the pokemon. Its webbed feet and strong fin tail allow it so swim through thick, dense water while its natural fire lung allows it to dive deep into the ocean. It has 'gills' on its stomach that actually separate water and pollution instead of water and air. The pollution is then added to its back, making it more toxic.
Oleum is a stage 2 pokemon and can evolve upon reaching a higher level.

Oleum created and designed by ME

created on Tegaki-e