Also Kaminari, Raidin or narukami
Japanese: 雷神, 雷様, 雷電 or 鳴神
Translation: Thunder kami

Raijen is a thunder kami, he is usually depicted as demonic looking. He had a drum on his back to produce the thunder. He is often depicted with Fujin in art.

He is known to eat the bellybuttons or abdomens of children. Raijen has a demonic companion Raiju who sleeps in bellybuttons and Raijen’s attempt to wake up his companion involve shooting arrows at him. The superstitious will sleep on their stomachs during bad weather to avoid this fate.

Raijen is a fairly popular kami with many pop culture references including several in the West (Mortal Combat, Big Trouble in Little China).