Defrog(デフロッグ Defuroggu) is the first Space Beast that appeared in Episodes 1 and 2 of Genseishin Justirisers.


Defrog has the appearance of a bipedal dinosaur with a wide, black-colored body, long hook claws in place for the hands, and a long tail. He has a Chinese dragon-like face with blank red eyes, two rows of teeth, and blue horns. His back is covered with big black spikes while there are big blue spikes sticking out more above his shoulders.


Appearance! Genseijuu Riseross

After an alien scientist named Dr. Zora awakens her master, Kaiser Hades, from his stasis on Earth, she sends out one of her Space Beasts called Defrog in the city. Defrog starts rampaging through the city with the Cyber Knight Zaurus commanding it. Later, after a high school student named Shouta comes across Zaurus and tries to run away, Defrog spots him and tries to kill him with it’s Mouth Beam. Fortunately, Shouta gets saved when Defrog it knocked down by a giant mecha dinosaur named Riseross. The two giants fight each other while Shouta make his escape. Defrog gets hit by Riseross’ claws when it launches them out, so the Space Beast uses it’s Mouth Beam but it has no effect on Riseross. As the two continue fighting, Zaurus has the Zakoal fight against Shouta, whom has become Riser Glen. After Riseross uses it’s double buzzsaws on it’s chest on Defrog, Zaurus tells the Space Beast to retreat. So Defrog teleports away in a puff of smoke.

Riser Glen, Kenzan!

When Zaurus tries to take on Shouta, he ends up getting incinerated when Shouts turns into Riser Glen. After Zaurus’ death, Defrog arrives back in the city and tries to shoot at Riser Glen with it’s Mouth Beam. As Defrog comes closer to him, Riser Glen is informed to summon Riseross from the Shadestar. Riseross arrives at the area and starts shooting Defrog from the sky before landing. Riser Glen boards inside the cockpit and controls Riseross to fight against Defrog. After a small fight, Riser Glen activates Riseross’ finishing blow, Zeross Cannon, and fires missiles from Riseross’ shoulders at Defrog, blowing the Space Beast up.


Capsule Form: Defrog can arrive at a location while in a form of a capsule that acts like a meteorite.

Mouth Beam: Defrog can shoot a blue beam from it’s mouth with the energy coming from it’s shoulder spikes.

Hook Claws: In place for it’s hands, Defrog has two giant hook-like claws.

Teleporting: Defrog can teleport away by glowing blue and disappearing into smoke.


  • Defrog’s Mouth Beam is reminiscent to Godzilla’s Atomic Breath.
  • Defrog is said to be roughly fifty meters long.
Community content is available under CC-BY-SA unless otherwise noted.