Well, first time trying original ones. I really don't get why there's no fire/fairy pokémons yet, they're quite an obvious an easy concept.

Lavaby: Lavaby is an ancient pokémon, only discovered recently because it rarely goes to the surface, living on the magma. Only comes out on eruptions, and when it does, you can hear it sing if you're close enough.

Maglody: A spirit of lava and fire. Its voice can revive inactive volcanoes.

Flamaria: The legends say that maglody can only evolve when lost of its group. It would sing with all its strength, and, if it survives, evolve. Flamaria's power is said to be ten times stronger than the Sun.