Bisonia was a Mammalian Warrior Beast featured on Episode 12 of the Great Mazinger Anime. He had a large dark blue Bisone-like body with a red lion-like head with a white mane and a pair of horns. It has a long tail and a large missile launcher on its back. Bisonia mainly uses the horns on its head as well as its hooves for close combat. It was capable to shape shift its appearance as a normal bull, although was larger than the others in the disguise, and would always create loud steel thuds sounds which each step. It features impressive defense able to take a hit from Great's projectiles and the massive hunch on his back was a massive missile launcher, which also contains wings, which would help it to fly. His true light blue face is located on the forehead and has red facial features.

The events are set in motion when a parade roams the streets, with an escort biplanes throwing leaflets on the city below. Shiro and Bakarasu the Crow, grab each a leaflet and take them to Tetsuya and Boss respectively, these promote a running of the Bulls competition, with the prize been a 10 day vacation for the winner and two others to Spain, both Boss and Tetsuya decide to enter. Unfortunately, Archduke Gorgon also learns this and deduces to Argos that Tetsuya will likely participate in the event, this is idea is shared the idea with The Great General of Darkness and General Rigern, who chooses an already disguise Bisonia for the mission. Bisonia is sneak into the Bull Pen as Tetsuya and Boss show up to compete.

Boss starts the event, dressed as a Matador, while promising to end Poverty and Unemployment (The later happens in the Spanish version lol) and confronts a very tired drunk Bull … who goes after him as soon he sees the red sheet and goes as one would expect for Boss, been run out of the field on his underwear (at least the Bull had some dignity for his opponent XD). Tetsuya is next and Bisonia walks out, not before killing the intended Bull by crushing its head. The Beast rushes straight to its target, to the amusement of the crowd and other competitors, do to its size, Tetsuya avoids its attack many times, before attempting and failing to stab it and is run over by the Beast. Some of the other competitors jump to help Tetsuya out, only to be gore by the beast, who then runs amok, even onto the crowd stands itself, as it attempts to kill Tetsuya. Above them, Rigern and Gorgon on the Mikelos fire as laser beam which removes the disguise and transform Bisonia on its real Warrior Beast form, and the crowd panics as the Beast continues its assault. Tetsuya orders Jun to take Shiro and get Venus while he distracts the Beast, Bakarasu flies back to Boss and warns him.

As Bisonia hunts Tetsuya down a mountain pass way, it fires its missiles to the rock, causing an avalanche that bury Tetsuya. Believing having accomplish their goal, Rigern orders Bisonia to attack the Science Fortress, Borot shows off, but Bisonia scares it off with its missiles. Boss notices Tetsuya's bike among the rubble and searches for and frees him. Venus A is launch to search for Tetsuya but finds Bisonia in her way and the two fight, but Venus is defeated and gore down onto a cliff and the ocean, the Fortress submerges for protection, but soon re-emerges to allow Tetsuya to enter and take off on the Brain Condor, Bisonia also takes flight as it attempted to stop the Condor from hooking up with Great Mazinger: succeeding at first, yet to no avail and Bisonia is force to fight the Mecha. After been Gore and Blasted with the rockets Tetsuya blasts its wings off with Thunder Break and unleashes its Great Sword for the fight forcing Bisonia into a Matador vs Bull rematch, with the lab staff watching and chanting “ole”. Having his moment of fun, Tetsuya sticks the Great Sword onto the ground, Blade upwards, Grabs the Bull by the Horns and takes off. Tetsuya then nose dives, letting the Beast go and having it impale in with the upright sword. Great Mazinger then dispatches him with the Great Burn.

With another defeat under his belt, an angry Emperor of Darkness berates the Great General for the lose.