Gasroid (Gasuroido) is the 47th Robot Kaiju of the Dark Horror Army and served as the monster of the week in the 40th Episode of the Dino Mecha Gaiking: "The Rose Spaceship".

_Appearance and Abilities_
The Gasroid was a Lizard like Dark Horror Monster Robot, sporting various tones of Green in its color scheme on its body, with an orange underbelly and Green/blue legs and sporting two purple horns on the head; its back sport rows of square fins. Interestingly, it was in its right one of the more powerful monsters of the army, simply by its ability to release a deadly purple gas cloud from its mouth: this gas, not only was it poisonous to all life, it was capable of melting Gaiking's legs. It would use its tail as whip to repel attacks.

The monster was revealed at the last minute, as much of the episode is hand-strong by Emelda's motives and romance with Sanshiro.

_Story_
After rejecting an interview with a journalist in regards to the Emerald Rose incident, the events of the story are told from Sanshiro's point of view, having been involved in a secret romance with a woman named Emelda (out of nowhere) and only spotted by Yamagatake and Hachiro who take a photo. After reaching a church, Emelda disappears in its grounds, only for a Rose like UFO, with an emerald glow, to lift off into the sky, surprising Sanshiro leaving only a small emerald rose ornament behind. Time later, the Emerald Rose UFO is spotted by a jet and avoids it; this is reported to the Daiku Maryu, which takes off looking for the elusive craft into space, specially Sanshiro, who seeks to see Emelda again and hasn't come back since last they met.

After days of search and using Sakon's Residual Magnetic Tracer, they follow the trail of the Emerald Rose and find it; the UFO enters into combat with the Daiku Maryu using its powerful Emerald Beam, busting its engines, and Gaiking is deploy for combat. Gaiking uses its weapons to no effect, as the energy glow of the Emerald Rose is also a defense shield. Gaiking is hit by the Emerald beam and its systems knocked out; the ship then takes Gaiking away into deep space unable to follow. Afterwards, with the engines fixed, the Daiku Maryu searches space for Gaiking, in the meantime, the group studying the photos taken by Yamagatake of Emelda, which she is shown to have glow similar to that to the Emerald Rose UFO. Gaiking is found but without Sanshiro on board.

Meanwhile, Sanshiro finds himself awakens in a room, explores its surroundings and sees images of a picturesque paradise like world; then Emelda appears, revealing herself as, the pilot of the Emerald Rose, an Alien of Planet Emerald and its Princess. Wanting to explain further, her conversation is interrupted by a called from the Four Zelan Generals, with Sanshiro listening close by. Refusing to give up Sanshiro to the Zelans, the Generals leave, not wanting direct combat with a Spacecraft with far greater power than their Grotestars, departing with the words that only they can help her Planet.

Trying to understand more, Emelda explains her world has been besiege by poisonous gas cloud coming from a nearby nebula, killing life on the Emerald Planet. Seeking help, Darius appears one day promising to help in exchange for the destruction of the Daiku Maryu, which Emelda agrees to take the task. However, Emelda wanted Sanshiro to help her destroy the Daiku Maryu, despite her pleads and emotions, the latter rejects, though expresses desire to help her world if both where to fight together against the Zelans. She traps Sanshiro in a tube and gasses him, knocking him out; when he awakens again, he finds himself on Earth, next to the Lighthouse. After explaining everything to the others, Sakon is incapable of helping, as their last combat busted the Central Computer, as well, Emelda made sworn a field of loyalty to Emperor Darius – meaning their next encounter will be a hostile one. Meanwhile, the Zelans decide to take matters into their own hands.

Later, the Emerald Rose returns to Earth for the final confrontation with the Daiku Maryu, who takes off to towards Mt. Fuji to face it, Sanshiro on the waiting ready to deploy, much to the conflict of his own emotions.

The UFO begins the attack, which the Daiku Maryu avoids, but the weapons of the latter who no effect on it due to its shield, but are hit by a dual Emerald Beam – Sanshiro is order to deploy Gaiking, but he rejects due to his emotions. This allows the UFO to uses it Leaf like blades to hit the Daiku Maryu and causing it to crash; Emelda comes back to strike the ship one more time, but sees Sanshiro on the cockpit on the Daiku Maryu and now she too has a inner conflict due to her own emotions for Sanshiro, both having a conversation with each other when suddenly, the alarm sounds off, as the same Poison Gas that afflicted Planet Emerald appears on the sky.

The Generals then appear in her screen, making their intents clears and revealing the truth of the Poison Gas and the monster that causes it, Gasroid, and what had now befallen her Planet, Emerald, destroy by using the Death Cross Phenomenon as it was no longer able to sport any life, thanks to the poison gas. As she has an emotional breakdown, and hearing the whole truth, Sanshiro deploys for battle with Gasroid, clearing the cloud around it with Desper Sight, then tries to strike with Counter Cross, but the monster repells with a tail whip. The blasts its poison gas, affecting Sanshiro and melting Gaiking's legs. Seeing Sanshiro in trouble, Emelda intervenes and gives the power of Emerald Rose to power Gaiking's Saur Gayser attack, team up as Sanshiro originally suggested. The Generals try to warn her this would be fatal for her in the end, but driven by the loss of her love ones and Planet Emerald, Emelad seek to make them pay. The combine effects of the UFO and the Gaiking begin to tear Gasaroid apart from the inside out as the Saur Geyser takes an Emerald glow – finally the Monster is destroy, but with the Power depleting, Emelda bids farewell and falls dead, the Emerlad Rose begins to dies, petals falling off. Finally it falls to ground, exploding on impact. Sanshiro screaming her name.

Reverting back to the present, Sanshiro looks to the small Emerald Rose Emelda had left behind that night, and bids farewell, promising to always love her.