Yatta-Ankou (alternately spelled Yatter-Angou) serves as a primary combat mecha for the Yatterman duo in their 1977 adventures. Designed by inventors Gan Takada and Ai Kaminari, it belongs to a trio of specialized robots alongside Yatter-Wan and Yatter-Pelican. Deployment hinges on Omochama, a cube-shaped companion robot, who rolls a die to select the active unit—Yatta-Ankou activates on results of five or six.

Later episodes replace this die-roll system with a musical chairs game orchestrated by the Janken Trio, three android girls symbolizing rock-paper-scissors gestures. Though this temporary method alters selection protocols, Yatta-Ankou persists in the operational lineup. While technical specifications of its design and combat features remain unelaborated, the mecha routinely confronts the Doronbo Gang’s machinations, often centering on clashes over the coveted Dokuro Stone.

Exclusive to the original 1977 series, Yatta-Ankou does not appear in later films, spin-offs, or crossovers. Its narrative remains strictly tied to episodic confrontations, with no additional backstory or evolution documented beyond these engagements.