Meaning "thunder animal/beast" it is a creature from Japanese lore said to be composed of lightning and may take the shape of a cat, fox, weasel, white wolf, blue wolf and even a wolf wrapped in lightning. It may also fly about as a ball of lightning with a cry that sounds like thunder. Raijuu is the companion of the thunder god Raijin. While the beast is generally calm and harmless, during thunderstorms it becomes agitated and leaps about in trees, fields and even buildings.
Raijuu can be contracted within the Old Metro instance and encountered as an enemy variation within Nakano Stone Site silver instance. He can only be fused after completing a quest for the cathedral master in Shinjuku Babel.
Shin Megami Tensei: Strange Journey
"A beast of Japanese lore, said to come down to Earth on a bolt of lightning. It usually runs through thunder clouds, but will also ride bolts of lightning down to the ground."
Raiju can be obtained by letting a Gremlin evolve at level 14. It can teach Flynn the Shock skill through its Demon Whisper. Raiju is one of the demons needed to summon Asterius through special fusion.
Shin Megami Tensei IV Apocalypse
Raiju can be found within the Sky Tower or by letting a Quicksilver evolve at level 30. Raiju can teach the Shock, Binding Claw and Tarukaja skills through its Demon Whisper. It benefits from learning Physical and Electricity skills.
Devil Summoner: Raidou Kuzunoha vs. The Soulless Army
"A beast of Japanese folklore, said to come down to earth on a bolt of lightning. It usually runs through the thunder clouds, but will also ride bolts of lightning down to the ground."
—Shin Megami Tensei: Devil Summoner: Raidou Kuzunoha vs. the Soulless Army Devil Chart
DemiKids: Dark/Light Version
"Charged with electricity, this demon descends from the skies on a lightning bolt."