Achigator "Crocalor"
About
Atop Crocalor's head is an orange mass of fire energy shaped like a nest, with yellow squares patterning it. This "nest" contains a yellow, glowing, egg-shaped fireball on top, borne out of Crocalor's fire energy and overflowing vitality. Crocalor can control the fireball, sending it out and using it for its moves. As shown in Pokémon Sleep, Crocalor and its evolutionary relatives are known to sometimes sleep with one eye open. The fireball on Crocalor's head never falls off even as the Pokémon sways rhythmically in its sleep.
Crocalor's internal flame sac has a valve that connects to its vocal cords. As a result, Crocalor lets out guttural cries as it releases fire from its mouth. Its voice can hardly be described as beautiful; moreover, its voice becomes more destructive as it breathes more powerful fire.
Evolution
Crocalor evolves from Fuecoco and evolves into Skeledirge.
(Source: Bulbapedia)