Combustus

Combustus is the boss of Ignus Cavern in Trimodulum.

Biology
Combustus appears to be a giant magtail with no orange spots at first, it's massive mndibles can pick up human-sized creatures and fling them around. It can roll into a ball to attack similar to king dodongo.

However upon enough damage, it becomes clear that the first stage was only a hard rock armor, it becomes cracked exposing an orange glow.

Eventually the armor completely cracks and reveals the true form of Combustus, this form resembles a skytail, skytails are enemies first appearing in skyward sword where link had to attack their bulbous tails.

This final form must be attacked in the bulbous tail in a similar manner to a skytail.

History
Combustus was a fossilized creature within Mt Ignus, it was awakend by mysterious causes and began flying around in the mountain, it's freedom from fossilization allowed magma to pour out and caused the volcano to errupt.

Link came to Mount Ignus and climbed near it's peak, he fought off a variety of creatures and eventually confronted combustus.

Despite his best efforts Combustus was defeated by Link, he fell into the Magma source and took down various rock fragments sealing himself and the magma within a subbterranean cavern full of lava.