ZenkaiOh Black JuraGaon (Japanese: ゼンカイオー ブラックジュラガオーン) is a villain mecha from the Japanese tokusatsu series Kikai Sentai Zenkaiger (2021–2022). It is a dark copy of the heroes' mecha ZenkaiOh JuraGaon and therefore not a machine of the Ranger team but the second Giant Robo of the antagonist Stacaesar. Built by the villain scientist Izirude, it is summoned when Stacaesar sets dark "Sentai Gear" versions of Juran and Gaon into his Geartozinger. Unlike the original, which houses two independent Kikainoid personalities (Zenkai Juran and Zenkai Gaon), Black JuraGaon possesses a single consciousness that obeys Stacaesar.

Like its heroic template, it forms from the combination of two individual mecha: the Black Juran Tyranno (Tyrannosaurus mode) and the Black Gaon Lion (lion mode), each forming one half of the robot's body. It wields copies of the Juran Sword and Juran Shield plus the Gaon Claw, which can fire a laser beam; uniquely, it can separate and generate a black hole that rebounds an opponent's attacks. Visually it is a black, gold and purple redeco of ZenkaiOh JuraGaon.

Collector note: ZenkaiOh Black JuraGaon never received a DX toy. It was produced solely in Bandai's Minipla candy-toy (shokugan) model-kit line as "Minipla Zenkai Gattai Series PB ZenkaiOh Black JuraGaon," a Premium Bandai exclusive. Preorders opened in October 2021 and delivery followed in March 2022 (retail 3,850 yen). The set contains one snap-fit plastic model (approx. 150 × 100 mm) with a piece of ramune candy, using metallic-colored parts and painted face details, and can also be built into intermediate forms such as the Black Juran Tyranno. Because Kikai Sentai Zenkaiger was never adapted into Power Rangers, the zord was never released as a Power Rangers toy — it is Japan-exclusive.