Neverwhere

Companion: Taal - Lava Frog Elder God
Lava frogs are a superstitious species with many myths regarding their gods, and, like most folktales, these stories have grown far larger than the truth. The simple truth is that lava frogs are nearly immortal due to their slow metabolism and natural regenerative abilities. A distinct lack of broodcare creates separation between each generation and though the adults may live in colonies, this rift breeds misinformation about those who came before. So it is that those lava frogs who live to see the centuries pass become regarded as legends, kings, and gods.
Taal is one such Elder God, asleep within the now-extinct volcanic ring that created the mountain range of Cielle. He appears to be no more than a large rocky outcropping atop a low mountain, though those who shelter beside him will notice an unnatural, but welcome, warmth emanating from his rough skin. He feels very like rock, and has slept for so many years that he has become covered in alpine lichen, so you might be forgiven for thinking him actual stone until he opens his large, glowing, yellow-orange eyes.
As might be expected of an Elder God, even one who is not actually a god at all, Taal does not move a great deal, or very quickly, rather, he expects his worshippers to come to him. He prefers his lonesome heights and the occasional quiet, sullen, companionship of the equally inhospitable Neverwhere. Also like most gods, Taal has no discernable interest in outing himself as entirely mortal or in stopping anyone who should choose to bring him tribute.
Despite his title and impressive size, due to his slow speed and lack of any actual magic, he poses no real threat to travellers that happen upon him.