Caesar Anthonio Zeppeli is a central character from the second major story arc of JoJo's Bizarre Adventure. He is a young Italian man of twenty years, born on May 13th, who stands 186 centimeters tall. Caesar is the grandson of Will Anthonio Zeppeli, a Hamon user who sacrificed himself to aid Jonathan Joestar decades earlier. Carrying on this complicated family legacy, Caesar becomes a pivotal ally and rival to the protagonist, Joseph Joestar, in their shared battle against the ancient super-beings known as the Pillar Men.

Caesar's background is marked by a profound and painful transformation. He was raised in Naples, idolizing his father, Mario Zeppeli, a master furniture maker who was devoted to his family. When Caesar was ten years old, his father abruptly abandoned the family without explanation, leaving Caesar and his siblings orphaned after the early death of their mother. The money left for them was stolen by a relative, and Caesar, filled with a growing hatred for the man he once worshipped, was eventually sent to an orphanage. His rage led him to escape and become a feared delinquent in the slums of Rome, committing theft, arson, and assault, but never murder. During this lawless period, he unconsciously displayed his innate talent for Hamon, striking opponents with a force that felt like an electric shock. At sixteen, he finally tracked down his father in the catacombs beneath the Colosseum. There, Caesar accidentally triggered a trap set by the sleeping Pillar Men. His father sacrificed his own life to save him, revealing that he had not abandoned his family selfishly, but to pursue a way to defeat these creatures. In his dying moments, Mario Zeppeli, not recognizing his son, begged him to deliver a message to a Hamon master named Lisa Lisa in Venice. This tragic revelation transformed Caesars deep-seated resentment into pride and resolve, and he immediately set out to honor his fathers will.

Initially, Caesar is presented as a stark contrast to Joseph Joestar. Where Joseph is a brash and cunning brawler, Caesar carries himself with the polished, flirtatious demeanor of a sophisticated Italian. However, this veneer of calm professionalism conceals a hot-blooded and impulsive nature. He is fiercely proud of his Italian heritage and the strong familial bonds it represents. His early interactions with Joseph are defined by conflict; Caesar looks down on Joseph for his lack of refined Hamon technique and blames the Joestar family for his own grandfather's death. Despite this rivalry, Caesar's sense of honor and duty is absolute. He is driven by the need to avenge his father, grandfather, and the entire Zeppeli bloodline by eradicating the Pillar Men. This quest for revenge is a core motivation, but it eventually becomes his fatal flaw, as his desire to strike without delay overrides his better judgment.

Caesar serves as a crucial ally and a lancer to Joseph Joestar, providing a more disciplined and technically skilled counterpoint to Joseph's improvisational genius. His key relationships define his arc. His teacher, Lisa Lisa, is a warrior he respects deeply, almost as a mother figure. His friendship with a German soldier named Mark, who is killed by the Pillar Men, further fuels his hatred for them. Most importantly, his relationship with Joseph evolves from bitter contempt to profound respect and brotherhood. After witnessing Joseph's courage and tactical mind in their first fight against the Pillar Men, he takes Joseph to train with Lisa Lisa. Through grueling training, they develop an incredible synchronicity in battle, able to communicate with a single glance.

Caesars personal development is a journey from bitter, angry orphan to a self-sacrificing hero. The revelation of his fathers true purpose allows him to let go of his past and embrace the noble Zeppeli legacy. He drops his arrogant facade and forms a true bond with Joseph. However, his old impulsiveness resurfaces when he learns of the Pillar Mens location. Frustrated by Josephs more cautious approach, Caesar storms off alone to confront them, believing the moment to strike is at hand. This decision leads to his final confrontation with the Pillar Man Wammu. In a desperate, brilliant fight, Caesar uses his unique abilities to push the powerful warrior to his limit. He ultimately falls, not from a lack of skill, but from a single second's oversight when his own body casts a shadow, allowing Wammu a fatal counterattack.

Caesar is a master of Hamon, which he channels primarily through soap bubbles, a technique he developed himself. His abilities demonstrate his creativity and deadly precision. He uses Bubble Launcher to fire a rapid barrage of Hamon-infused bubbles. His signature technique, Bubble Cutter, creates disc-shaped bubbles that spin at high speed, able to slice through solid objects. He can also create a Bubble Barrier to trap an opponent. A more advanced application, Bubble Lens, uses these flat, disc-shaped bubbles to refract and focus sunlight into powerful, searing beams. In his final moments, with his body broken, he performed the Last Hamon. Using his own blood, he created a single bubble infused with the last of his energy, sealing inside it his headband and the antidote ring he tore from Wammu`s lip that could save Joseph from a deadly poison. As the ceiling collapsed, crushing him under a cross-shaped stone, his blood bubble floated away, a final act of friendship and sacrifice that allowed Joseph to continue the fight. Caesar Antonio Zeppeli died as he lived, driven by the powerful legacy of his family to protect those he came to care for.