Mappo No Ryujin

Mappo no Ryûjin is a Great Old One created by Chaosium for the Call of Cthulhu RPG in 2005.

Mappo no Ryûjin is a Great Old One which is currently bound and slumbering in an eight-pointed Elder Sign in the Muvian ruins near the Japanese isles. Currently she is active in a semi-corporeal form. The last time she visited Earth was 50,000 years ago, when Yig unleashed it to punish the Serpent Men who were worshiping Ghatanothoa and who had joined forces with the island civilization of Mu to create a new hybrid race of humans and Serpent Men. In one night, most of Mu and parts of Lemuria sank beneath the waves. The last act of the dying Muvian wizards bound Mappo no Ryûjin to the Elder Sign.

It is believed that at the twilight of the age of man, when the celestial bodies are in perfect alignment, she will bring forth an orgy of destruction, as the sixth race emerges to take over the world. The Mother of Yig will devour the sun and darkness will reign for 666 days. She is a 1000 ft long entity with two skeletal wings, a desiccated oriental dragon head, and 666 pseudopos covering its white skin. Each of the pseudopods looks like a giant albino snake, which are used to swallow and consume living creatures, each thick enough to contain a human victim. Which are covered with a slimy mucous containing digestive acids.

Also known as

Mother of all Snakes
Harbinger of Doom
Tien Lung
Azhi Dahaki
the Mother of Yig

Mappo no Ryujin, the Harbinger of Doom, and Mappo's Dragon, is a powerful Great Old One that is described as being a dragon-like entity, and covered in pseudopods.

What is more is that it is egarded as the mother of the Snake-God Yig and said to be imprisoned beneath the sunken continent of Mu.

It is believed that Mappo no Ryujin once attempted to devour her child when he hatched, but managed to escape by poisoning her stomach in forcing her to regurgitate the would-be snake god, making his escape.

She is imprisoned deep in the ocean underneath a sunken city that once neighbored Sendoru.

Mappo no Ryujin is a Great Old One, the whole of her body is corrupted flesh of Jormungandr (the very same that gave form to Yig). She is a writhing winged serpent covered in pseudopods that exude a foul ichor. When Yig was born of a ruptured pustule on her back she attempted to devour him, but he proved too poisonous for even herself to stomach and was forced to regurgitate them.
