Mad Saurus commands Sector B, a gang of criminals, bikers, and psychotic killers inhabiting the buried ruins of Evil Town. Towering over two meters tall, his heavily scarred visage features missing teeth, a blind eye, and patches of missing skin around the eye socket, amplifying his intimidating presence. He possesses exceptional physical capabilities—strength, speed, and endurance far exceeding normal humans—enabling brutal hand-to-hand combat.

After a catastrophic earthquake submerged Evil Town, Mad Saurus and his gang initially cooperated with rival Sector A to secure essential resources like food and supplies. Once survival seemed assured, both factions descended into extreme violence and widespread abuse against the women of Sector C. Mad Saurus voiced no moral objection to his gang's systematic rape and murder, reflecting his chaotic cruelty. He maintained a close bond with Blue, a hermaphrodite who served as both his second-in-command and romantic partner. Their relationship appeared genuine, marked by Blue's unwavering loyalty and Mad Saurus's clear emotional attachment.

The arrival of Violence Jack altered the power balance. Jack initially allied with Sector A but switched sides upon witnessing their brutality, matching Sector B's. This triggered open conflict where Mad Saurus played a decisive role in defeating Sector A, personally killing their member Kawamori during battle. He then directed his forces against Sector C. During his first direct clash with Violence Jack, Mad Saurus was overpowered, thrown through a stone wall, and severely injured, temporarily incapacitated.

While he recovered, his gang abused Sector C's women until Violence Jack intervened, slaughtering the gang members and dismembering Blue. Returning to find Blue's corpse, Mad Saurus exhibited intense grief, weeping over her body. Consumed by despair and a desire for vengeance, he consumed her remains believing it would merge their power. This act triggered a grotesque physical transformation into a red, demonic abomination with enhanced strength—an event exclusive to the OVA adaptation, not the original manga. In this monstrous form, he battled Jack, seizing Jack's signature knife and stabbing him in the chest. Despite this momentary advantage, Violence Jack overpowered him, impaling the knife into Mad Saurus's head. The fatal injury reversed his transformation back to human form. In his dying moments, he experienced hallucinations of Blue before succumbing. His motivations throughout stemmed from ruthless ambition, a drive to dominate Evil Town, and a perverse yet genuine love for Blue that fueled his final, destructive actions.