Gaira, a humanoid sea beast spawned from the discarded cells of Frankenstein's monster, attacks the shores of Tokyo. While the Japanese military prepares to take action, Gaira's Gargantua brother, Sanda, descends from the mountains to defend his kin. A battle between good and evil ensues, leaving brothers divided and a city in ruins.
as Dr. Paul Stewart
as Akemi
as Dr. Yuzo Majida
as Dr. Kita
as General
as Police Chief
as Police Officer
as Sailor
as Singer
as General's Aide
as Soldier
as Soldier
as Defiant Reporter
as Skeptical Reporter
as Fisherman #1
as Fisherman #2
as Official
as Dr. Paul Stewart (voice)
as Gaira
as Sanda
as (uncredited)