A. Sutherland – AncientPages.com – In Japanese mythology, Raijin (Raiden) is one of the eight gods of thunder, and master of lightning. His attribute is a sacred Taiko drum. He is commonly represented together with his brother, Fujin the god of the wind, but his personal companion is Raiju (“thunder animal” or “thunder beast”).
Thunder God Raijin and Wind God Fujin. Kyoto National Museum. source
The beast is described as looking like a cat, badger, ball of fire, ball of lightning, weasel, monkey, Tanuki (Japanese raccoon dog), a white and blue wolf, and a wolf wrapped in lightning (its body is made of lightning and its cry sounds like thunder).” 1
Raiju is a demonic creature, usually harmless and calm but he loses his temper only during thunderstorms. He then becomes extremely agitated, leaping around in trees, open spaces, and among buildings. In Shinto beliefs, trees that have been struck by lightning were said to have been scratched by Raiju’s claws. Another Raijin’s companion is a thunderbird Raicho, a pine dweller, which – as myths tell – is often sighted flying through a stormy sky.
Our knowledge of the god Raijin comes from Kojiki (“Records of Ancient Matters”), written in 673-686 AD. It is the oldest Japanese book and the most complete collection of Japanese Shinto myths, oral traditions and partly historical accounts down to 641 AD.
In the early Shinto beliefs, the central deities and creator gods, Izanagi and Izanami are parents of Raijin, who born from Izanami’s corpse when she was in the land of darkness (Yomi).