Spectreman Wiki

Thunder Gei
Subtitle Cyborg Monster (サイボーグ怪獣,   Saibōgu Kaijū?),
Flying Whale (空とぶ鯨,   Sora tobu kujira?)
Aliases None
Status Deceased
Gender Unknown
Species Cyborg
Physical Information
Forms Giant,
Height N/A
Length Microcelular - infinite
Weight 20,000 tons - infinite
Eye color Black,
White (when glowing)
Relationships and Affiliations
Controlled by Dr. Gori
Allies None
Enemies Spectreman
Other Information
First appearance Spectreman episode 17, "Thunder Gei, The Flying Whale”
Latest appearance Spectreman episode 18, “Infiltrate Monster Island!”

Thunder Gei (サンダーゲイ,   Sandā Gei?) is a cyborg whale kaiju that appears in episodes 17 and 18 of Spectreman.


  • Spectreman episode 17: "Thunder Gei, The Flying Whale"
  • Spectreman episode 18: "Infiltrate Monster Island!"
  • Spectreman manga


Spectreman (series)[]

Thunder Gei takes on a whale-like design. It is light blue in color, has a huge head, huge mouth with whale-like teeth in it, a pair of small eyes and two pairs of fins, one under the head and one under the tail.

Spectreman (manga)[]

Thunder Gei's design is changed in the manga. Its eyes are bigger, it has two big fags pointed upwards on its lower jaw and an armor on its head running down to its tail with spikes on it.


"Thunder Gei, The Flying Whale" (episode 17)[]

Created by Dr. Gori, Thunder Gei attacked the ships around the Sea of Japan with little remorse. Attacking like a phantom, the creature crippled Japan’s fishing business. So it wasn’t long before Jouji transformed into Spectreman, and took on Dr. Gori’s latest threat. Using his Spectral Eyes, the warrior spotted the whale and immediately set out after it. each time he neared the creature, it flung him back to Earth; thanks to its electrical waves. Eventually though, Spectreman was able to blast the creature out of the sky, sending it crashing into the ocean.

"Infiltrate Monster Island!" (episode 18)[]

During their second battle, Spectreman finally was able to discover the whale’s weakness. The creature would mimic his moves. If he shrank in size, so would the monster. If he drained his strength and lay still, so would Thunder Gei. Dr. Gori, angered by his creature’s weakness, sent Karas to kill Spectreman in his weakened condition. The man ape attacked viciously, as Spectreman was forced to remain still and take it. Meanwhile, the Pollution Control team was putting a bomb inside the whale, as it laid still. Once they had finished they blew the creature up, leaving Spectreman now with the opportunity to whoop Karas once again.

Spectreman (manga)[]

Thunder Gei reappears in the Spectreman manga rampaging in cities creating earthquakes and tsunamis.


  • Lightening Bolts: Thunder Gei can launch bolts of countless volts of electricity from its massive mouth.
  • Electrical Shocks: When an opponent gets too close, Thunder Gei can generate massive amounts of electricity and surge it through its body to shock them.
  • Mimicry: Thunder Gei’s primary means of attack is mimicry, thus it will copy an opponent’s move, gaining it such powers as size changing to match whatever its opposition does.
  • Invisibility: With the ability to wrap itself in invisible waves that reflect the light spectrum of Earth, Thunder Gei can attack without warning.
  • Flight: Thunder Gei can fly.
  • Size Change: Thunder Gei can change its size just like Spectreman.


  • Thunder Gei uses slowed down dinosaur roars originally from 1960’s The Lost World and the Voyage to the Bottom of the Sea TV series.
  • Thunder G is portrayed using a model, a marionette and a suit.


Production Images[]

Television Screenshots[]


Spectreman Kaiju and Aliens
HedoronBakulahDeceitmanDust ManGilagindGokinosaurusKuruma-NikurasBaronsaurusMagulahMidoronMitsu Kubi RyuMogunetudonMogzNeo HedoronNezubirdonSalamandarSatan KingSilver RoboSpincobraThunder GeiZariganidZeronVegaronSphinxSphinx-Beast