Ghost Mechanical Beasts Gusios βIII (Beta3) was a amphibious Walrus like Monster, first presented close to the end of episode 68 and saw action against the Mazinger Team on Episode 69 of the original Mazinger Anime, this marked the introduction of Gorgon and Ghost Beasts into the series. Gusios, was a Ghost Mechanical Beast, which similar to the Warrior Beasts, were part machine and organic, tho lacking the Human Brain, these been prototypes to the Warrior Beasts – however is possible Gusios had some level of sentience. His shape was that of a Walrus, but with a torso, Three sharp spikes on its back, humanoid arms and hand hands, which allowed him to jump far on land, and his tail was lizard like, perfect to propel him underwater, adorn with a Trident at the end of it. He is invisible to long distance radar until close proximity, making it a foe difficult to fight. Resistant to energy attacks, he was able to Fire lasers from his eyes, breath super hot flame from his mouth, and emit electricity from his tail. When his energy was depleted, Gusios would use his sharp teeth to rip and devour metal as means to restore his energy. Gusios was notable for destroying the Hoover Pilder, an action that led to the creation of the Jet Pilder, and was one of 2 Ghost Mechanical Beasts to have a Roman Numerical rather than the Latin Number in his name, the other been Poses OII (Omega2).

After agreeing with his alliance to help Dr. Hell, Gorgon called forth Gusios βIII by the end of Ep.68 and heads to Japan just as Skeleton O7 is destroyed. In the following episode, marks the introduction of Bakarasu into the animated series - the Crow that harasses Boss to the point of him losing his patience. Boss then hunts Bakarasu on the Borot and insanity ensues, which to his dismay ends in humiliation, falls and cliffs at every turn. Boss, beaten and tired, makes it with a batter Borot to the lab, where, to his horror, sees Bakarasu, having befriended Koji and the other Staff members. Boss demands that the crow be given to him, so he can cook him and eat him, only to be denied by Koji and the others, Boss leaves vowing retribution.

Elsewhere, in the cost, Bood and Gusios surface, and Ashura demands a demonstration of its power, which does so by blasting fire on a rock, melting it. Impress, Ashura orders Gusios to head to the Photon Power lab and destroy Mazinger – which Gusios does after thrashing water onto Ashura and his/her men, causing Ashura to call Gusios as arrogant as Gorgon. As the Beast heads to the Photon Power lab, his proximity is not detected on radar. Meanwhile, Bakarasu explores the facility after horribly teasing Sayaka and the others, sneaks into the Command Tower pulls a prank by turning on the alarm and taking the Microphone – Koji launches Z and explores the area, unaware of the real danger, as Z and Gusios cross paths and the two fight, Gusios opening fire while avoiding Z's attacks, but the Beast sneaks away. Koji returns and informs, to the surprise of everyone, of the new Beast, and releases a grounded cage Bakarasu as reward.

Some miles away from the lab, Gusios watches his objective from a cliff, when an irritated Ashura arrives berates him, Gusios turn aggressive by blasting his car and Ashura apologies, realizing he can't control this beast as the others created by Hell. Ashura begs him to proceed with the attack and Gusios makes his move, this time Bakarasu, keeping watch warns everyone, at first not been believed, until the radar picks the Beast up at close proximity, the lab is put on high alert and the energy shield if activated too late and it is now inside of the perimeter and attacks, Koji takes off on the Hoover Pilder, but gives Chase and land over the Pool, blocking the Mazinger's exit, Gusios then melts some of the steel structures around the pool, including one made of Alloy Z and eats them, realising not to risk Mazinger would not be useful at the present time, not far Ashura watches the with joy as Gusios destroy the facility. Koji opens fire with the Pilder, but the rockets have no effect, Gusios retaliates, Koji avoids the laser, but is trashed by its tail, Koji avoids a crash, but the glass shield is total forcing Koji to rip it open to have visibility.

Realizing the severity of the situation, Prof. Yumi lifts Mazinger up via through the floor – this causes a collapse of the pool, which makes the Beast fall into the pit and covered by rubble, however, the Pilder's Hoover wings, damaged by the thrashing, can't fold up, impending it to lock, Sayaka comes out on the Aphrodite and uses her rockets to blast the wings off, helping the Pilder to land and Mazinger comes into action just as Gusios breaks free and once again it escapes, Koji then takes flight on the Jet Scrander and Bakarasu tags along to be Koji's improvise radar and does, but the monster avoids his attacks and uses the Woods for cover. Bakarasu explores the woods only to find the Borot gang prepping a trap for the Crow, he tries to warn Boss, he ignores, it enter in an argument, and Borot falls on his own trap ... AND THEY ARE OFF TO THE RACES, with Borot on his feathery tail.

In the chase Borot falls and stumbles onto the Gusios, who captures him and proceeds to electrocute him, Bakarasu warns Koji and Z flies to assist Borot, only to zap him, as Gusios used him as Shield. The Beast then hits Z in the back of the head, causing more damage to cockpit. Koji fire the Rocket punches to hold the tail as Gusios was about to thrash Borot onto him, he then tries to fire the Breast of Fire, but these don't response. Koji then releases the punches, which causes Gusios to lose balance and roll, he opens fire with the missile drills, which hit the monster in the face, and with the iron cutters, cuts the monsters neck and tail, the later freeing Borot. As it reels in pain, Koji fires his Photon Beam dispatching Gusios rapidly. Watching the events, an irritated Brocken curses Z for his victory, but a more attentive Dr. Hell notices the damage done to the Pilder, viewing it as a victory. Back on the lab, Yumi suggest to build a new Pilder, as Borot still runs through the woods after Bakarasu, not to eat him, but beg him for his help … of course Crow poops on him and the he resumes he crusade after the little bastard.

Gusios was featured in the original Manga as well the manga series Mazinger Angels.