Dodekai-Oh is a large auxiliary mecha from the 40th Super Sentai series, Doubutsu Sentai Zyuohger (2016). In the show, the Zyuohger team — Zyuoh Eagle, Zyuoh Shark, Zyuoh Lion, Zyuoh Elephant and Zyuoh Tiger, later joined by Zyuoh The World — fight using the Zyuoh Cubes, animal mecha that unfold from compact cube shapes. Dodekai-Oh forms from the largest of these, the Cube Whale; the name plays on the Japanese slang word "dodekai," meaning "huge/enormous." Because Zyuohger was never adapted into its own Power Rangers season, there is no official US name, and the mecha was never released as a Power Rangers toy — it remained Japan-exclusive.

The series is built around a cube gimmick: each animal is stored as a flat block and folds out into its combat form. The Cube Whale is the bulkiest of these and can transform on its own into the robot Dodekai-Oh (hence "Doubutsu Henkei," a single-cube transformation). Its main role, however, is large-scale combination: together with Zyuoh King and Zyuoh Wild (which themselves join to form Wild Tousai King), the Cube Whale merges into the massive Wild Tousai Dodeka King, one of the series' largest gattai formations. The whale can also take in smaller cubes, acting as a carrier and storage form.

The DX toy "Doubutsu Henkei Dodekai-Oh" was made by Bandai Japan and released in 2016 alongside the series. Like the entire Cube line, it is built predominantly from plastic and relies on the fold-out cube principle rather than conventional transformation; meaningful die-cast content is not characteristic of this line. It works both as a standalone robot and as an add-on compatible with the separately sold DX Zyuoh King and DX Zyuoh Wild, allowing assembly of Wild Tousai Dodeka King. Owing to its size it is one of the bulkier single pieces in the Zyuohger toyline. It was not distributed outside Japan through Bandai America or Hasbro.