Flint Hammerhead, born Genshi, is a prehistoric caveboy renowned for his immense physical strength, honed through feats like wrestling dinosaurs and hefting boulders alongside his father, Rocky Hammerhead. Their lives shifted when confronting the antagonist Petra Fina, who fossilized them during a clash over the Time Shifter Getalong. Centuries later, siblings Sarah and Tony Goodman unearthed their remains in the 25th century, leading Dr. Bernard Goodman to revive Flint fully while Rocky emerged as a sentient stone axe—Flint’s loyal advisor and weapon.

As a Time Detective for the Time Police, Flint traverses history to recover Time-Shifters scattered by the Dark Lord, safeguarding timelines from disruption. Preferring brute force, he leans on Sarah and Tony’s tactical insight. His energy wanes without constant sustenance, a vulnerability exploited in prolonged battles. Flint’s primal speech, marked by the catchphrase “Ishi-ishi-uho!” in Japanese, and gestures like chest-touching greetings often baffle modern companions, underscoring cultural gaps.

The manga expands his origins: a bond with a Tyrannosaurus, chaotic outbursts when misbelieving Dr. Goodman devoured Rocky, and reckless acts like hurling cars during pursuits. Unlike the anime’s memory-erasing protocol, the manga permits subtle timeline tweaks, testing Flint’s adaptability.

Central to all narratives is Flint’s bond with Rocky, whose axe form fossilizes foes—though ineffective against malevolent adversaries. Flint’s missions intertwine with historical figures, such as bolstering Miyamoto Musashi’s resolve, blending timeline preservation with personal growth.

Spin-offs maintain Flint’s core traits—raw power, loyalty, and temporal guardianship—while tonal shifts occur. Bom Bom Comics injects darker humor, depicting Sarah as less disciplined and Petra Fina’s villainy through the Dark Lord’s indirect manipulation, revealed via flashbacks. These variations highlight Flint’s unwavering resolve across timelines and media.