Mushussu is a mythical hybrid from Babylonian lore, a dragon with the hind legs of an eagle, a long neck and tail, a horned head, a snakelike tongue, a crest and a feline's forelegs. Mushussu is associated with Marduk and his assistant and sometimes son Nabu, often acting as a steed for one of the gods in art. It was originally a symbol of the obscure god Tishpak, who was conflated with Marduk.
In an episode from the Book of Daniel attested in the Septuagint but not in Hebrew and Aramaic versions, the protagonist confronts a dragon said to be worshiped by Babylonians. As the narrative mentions the worship of Bel, which was a title of Marduk, it's possible this is a reference to the mushussu.
The constellation known as Hydra among ancient Greeks was associated either with mushussu or with another monster, bashmu, by the Babylonians.
"A beast of Babylonian origin. Its name means "angry snake." It has the head and body of a snake, the front legs of a lion, and the hind legs of a scorpion. It is one of the 11 beasts that serve Tiamat and fought with the god Marduk. For some reason, it is often later depicted carrying Marduk on its back."
—Shin Megami Tensei: Strange Journey compendium
Shin Megami Tensei IV[]
A NPC Mushussu can be found in the Tokyo - Bay Area at the Fukagawa Fudo, acting as an agent of the Great Mother Goddess Mami in the delivery quest Recreating the Human Race. Seeing that Flynn is no ordinary human, he tells him the story of the goddess and introduces himself, asking for the ingredients necessary for Mami to make a new kind of human. Once the ingredients are acquired Mushussu finds it a shame that more humans aren't as useful as Flynn, as that would mean Mami wouldn't need to make new ones. Mushussu asks Flynn to bring more ingredients should he get some.
Mushussu can be found in Minami Sunamachi. It can teach Nanashi the Ziodyne, Posumudi and Axel Claw skills through its Demon Whisper. Mushussu benefits from learning Electricity and healing skills. Mushussu can evolve into Tiamat upon reaching level 52.
