Gakuma (ガクマ) were a pair of monsters that lived on Kurara Island (久良々島 Kurara-jima) that appeared in the series Ultraman Tiga. They appeared in episode 2.

Subtitle: Rock Monster (岩石怪獣 Ganseki Kaijū)


Ultraman Tiga

The Gakumas were monsters that have lived underground for years, happily eating rock. However, once their home was disturbed by a construction crew who began to take their rock away, the monsters began to rampage to drive off their invaders. The first was Gakuma Alpha who surfaced and attacked the crew, solidifying everyone and everything in sight with its stone beam. GUTS arrived on the scene just as Gakuma Alpha was attacking, and using its new weapon: the Dexus Beam, Gakuma Alpha was destroyed in one shot.

A short time later, Gakuma Beta then surfaced and picked up where its younger brother had left off, solidifying anything it saw, until it turned its attention to GUTS. Daigo was able to turn into Ultraman Tiga just in time and the two battled. Gakuma Beta's extra array of weapons proved too much for Tiga to handle, and the Ultra was quickly put in a fix when the Gakuma fired its stone beam at the Ultra, slowly solidifying him. Fortunately, the rock coating was destroyed once Tiga transformed into Power Type. The tide of battle turned in Tiga's favor, and he attacked Gakuma Beta until the monster was destroyed by Tiga's Delacium Light Stream.


  • Suit Actors: Hiroyuki Okano (Alpha) and Toshio Miyake (Beta)
  • It is assumed both Gakumas can use the same powers.
  • The Gakumas shares the same subtitle as Sadola.
  • Gakuma roars are actually heavily modified elephant trumpets.
  • Although not physically seen, one of the Gakumas is one of the monsters that makes up Belyudra's Right Arm in Mega Monster Battle: Ultra Galaxy Legends The Movie.
  • Gakuma Alpha is the first monster defeated by GUTS without Ultraman Tiga's assistance.
  • The costume for Gakuma Beta is currently on display at Ultraman Land in Kumamoto, Japan.
  • Gakuma resembles Zambolar.
  • In early planning for episode 2, the Gakumas had several different names such as Radom in the first final draft, the very final drafts calling them Gag, and character designer Hiroshi Maruyama and assistant director Takashi Hamada remarking that Genma was also considered.
  • Originally the episode's setting was not meant to be an island, but rather an overseas location like the US. Why this was rejected is because there was not enough time to build scale cities and streets.


Gakuma (Alpha)
Gakuma alpha

Gakuma (Alpha)

Gakuma (Alpha) (ガクマ(α) Gakuma (Arufa))

  • Height: 58 m
  • Weight: 56,000 t
  • Origin: Underground Kurara Island
Powers and Weapons
  • Stone Beam: Gakumas can fire a blue ray from their mouth, whatever is hit by the ray is coated in stone.
  • Burrowing: Gakumas can burrow at moderate speeds.

Gakuma (Beta)
Gakuma beta

Gakuma (Beta)

Gakuma (Beta) (ガクマ(β) Gakuma (Bēta))

  • Height: 59 m
  • Weight: 58,000 t
  • Origin: Underground Kurara Island
Powers and Weapons
  • Stone Beam: Gakumas can fire a blue ray from their mouth, whatever is hit by the ray is coated in stone.
  • Burrowing: Gakumas can burrow at moderate speeds.
  • Electric Pulse: Gakuma Beta can release an electric shock from around its body when an opponent is grabbing with it. Gakuma Beta can also fire purple electric bolts from his back.
  • Claw Extend: Gakuma Beta's front claws can extend into sharp objects to be used as weapons.



Gakuma Beta and Alpha were both released by the Ultra Monster Series. First to be released was Gakuma Beta in 1996 with four points articulation. But the brown is not on him and the horns have all yellow instead of orange and yellow. Then Alpha was released with the same point of articulation and with a more accurate paint job. Both Gakuma's are great in design.


Ultraman Tiga Kaiju
Ultraman Tiga Golza | Melba | Gakuma | Kyrieloid | Ligatron | Sealizar | Gazort | Critters | Alien Reguran | Different Dimension Witch | Gilanbo | Saki | Machina | Gagi | Evolu | Leilons | Alien Raybeak | Alien Muzan | Rucia | Zara | Gazort II | Sakunaoni | Abolbus | Redle | Fire Golza | Gobnu (Vaha) | Gobnu (Giga) | Gobnu (Ogma) | Enomena | Deban | Magnia | Magnia Parasites | Dinosauroid | Naga | Weaponizer | Litomalus | Kyrieloid II | Silvergon | Gagi II | Shadow | Obikoboushi | Jobarieh | Maya Cruz | Alien Natarn | King Molerat | Morat | The Life Form of Planet Bizaamo | Bizaamo | Shiela | Vampires | Kyuranos | Small Desimonia | Desimonia | Alien Desimo | Guwam | Goldras | Alien Manon | Dethmon | Faldon | Galra | Bakugon | Iludo | Virtual Alien Muzan II | Virtual Alien Raybeak II | Karen E-90 | Faivas | Geozark | Guarde | Gijera | Terra | Nook | Taraban | Metamorga | Illusion Evolu | Menjura | Charija | Yanakargi | Zoiger | Gatanothor
Ultraman Tiga: The Final Odyssey Shibito Zoiger | Golza | Demonzoa
Ultraman Tiga Gaiden: Revival of the Ancient Giant Degouf | Jomonoid | Kurayaminoorochi | Dogouf
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