Jiga Jiga was the 77th Monster by order of appearance that was featured in Ep.71 of the anime UFO Robot Grendizer; piloted by General Morros, it was the last Vega Beast created on Planet Vega just before its destruction, and is among the few Monsters NOT destroyed by the heroes.

Jiga resembles a Pegasus, but with a skeletal aspect – a skull and bones in limbs and tail – each limb ended on claw feet rather than hooves; it has and black body with purple joint ports, white abdomen, with bat like bronze color wings. Beside flight and deep space travel, Jiga sport a driller in the torso right below the neck and fired a laser beam from it eyes.

Jiga's present aspect differs from its intended original look, as head, limbs and tail had skin mass, sporting a mane and hair on its tail; however, as the Beast was still been made during the evacuation, it was abandoned by the army, when Morros found it; he took off on the Beast right as the planet exploded been pushed away; on its three month travel, exposed by meteors and space radiation, burned its mane and tail, and wither the skin from its head, neck and limbs, giving its current look.

As the King, General Gandal and Minister Zuril hold a meeting, a Vega Beast is detected approaching the Skull Moon Base; Zuril identifies it as Jiga Jiga, who went missing during the evacuation of the King and Army, and informs its pilot is General Morros, one the King knows, as it was the Prince of Planet Morros, another world conquer by Vega one year prior.

On Earth, Duke wakes up from a nightmare of his time on Planet Fleed during the invasion; running with Morros (an exchange student at the time) from the chaos, when the prince is tossed over the edge of a building; trying to save Prince Morros he was wounded by a laser shot, developing his scar on the right arm – this contradicts the idea before this wound was a product of Vegatron Bomb radiation. Feeling his strength waning and the poison closing in on his chest, Duke wishes to live long enough until Vega is defeated.

Morros has his meeting with the King, explaining his tail of survival and long journey to Earth, to provide help, to the king who saved him, in fighting Duke, who he blames for the Destruction of his Planet, but collapses and is taken to medical treatment.

The next day, Duke and the team, start their patrol as the King, appreciating Morros' loyalty valor, makes him commander of the Army for the attack, giving him a Shield medal; the General then takes off to Earth on Jiga with a squadron of Midifos accompanying it. Gandal, not understanding why the Prince of Morros, a planet conquered by Vega, would help them, which learns from the King Morros was captured after the conquest of Morros, delivered to him and brainwashed, implanting the story Duke Fleed was responsible for his planet's destruction, hence his thirst for revenge. The Flotilla is detected and the Heroes are warned, with Koji meeting the attack force first; he successfully shuts down some of the Midifos but Morros/Jiga end up shooting Koji down; Duke/Grendizer arrive and destroys the remaining attackers, then ejects to save Koji from a crash.

Morros lands and identifies himself, and we learn from Duke what happened in a flashback - Duke indeed, saved Prince Morros using his scarf which he held on to as gratitude (which unbeknownst to him due to the brainwash, wears on his neck to this day) this allowed Morros to escape Fleed and return to his home planet – When the flashback ends, Duke is horrified to learn his dear friend blames him for Morros' fall, suspecting his been brainwashed.

The two Mechas fight, with Morros proving the far superior pilot over Duke; Koji tries to help but is shutdown; Morros tries to destroy him, but his block by Grendizer's Anti Gravity storm, then gets in the way of laser hit from Jiga, Grendizer hits the ground with such force, Duke is ejected from the cockpit through the windshield; Jiga lands, and Morros comes out to shoot him, with Duke begging his friend to remember their friendship, which confuses the former. King Vega, watching the display, activates a switch, having hidden a micro bomb in Morro's shield; Duke realizing this, dashes to Morros, throwing the Shield away, exploding, tossing the two. Duke runs to check on his friend who wakes up with his memories restored.

Feeling remorse, Morros, remembering his debt to him, sets his gun and fires at Duke's arm, the latter falling unconcious; However, when Koji finds him, Duke wakes up to find his arm heal, but Morros nowhere to be seen, having left a farewell message to Duke written in the Snow; Morros, now piloting Jiga Jiga once more, flies back to the Moon Base to seek his revenge on the King, but another bomb. implanted on the Beast goes off, setting the Monster in flames; in one last act of defiance, Morros fires Jiga's Optic Beam to the moon, before the last of the explosives detonates, killing him.

From the blast cloud, Morros' scarf falls back to Earth as the arctic wings erases his final message in the snow.