Otomo Nin UFOmaru (相棒忍 UFO丸) is one of the Otomonin — the "partner ninja" mecha of Shuriken Sentai Ninninger (2015) — which the Ninningers summon by means of Nin Shuriken. Its motif is a flying saucer, thematically tied to space and the sky, and it made its debut in episode 5. In the US adaptation Power Rangers Ninja Steel / Super Ninja Steel, its counterpart is the Astro Zord. UFOmaru is not a standalone main Megazord but an auxiliary Otomonin that expands the firepower of the core robot Shurikenjin.

From its UFO configuration, UFOmaru converts into a self-contained humanoid robot that can be seated on Shinobimaru's "throne" within Shurikenjin. Together with Shurikenjin it forms the combination Shurikenjin UFO: the remaining UFO structure becomes a new Shuriken helmet as well as a large three-barreled cannon (the UFOmaru Launcher), with the associated finisher named UFO Big Bang. In this configuration Shurikenjin is able to fly into outer space.

The DX toy was released in March 2015 by Bandai (Japan) as "Otomonin 02 UFOmaru" (the successor to Paonmaru), retailing at roughly 2,800 yen. It is made predominantly of plastic; no die-cast content is documented, which is also typical for the auxiliary Otomonin sub-line. It includes its own Otomonin Shuriken (UFO) — noticeably more square in shape than other releases — which triggers the combination. The figure transforms from UFO to robot mode and attaches to Shurikenjin via the Shuriken, with the central section serving as a three-barreled blaster. Built-in electronics play sound effects (activation, attack and summoning sounds plus a dedicated combination jingle) and are powered by LR44 button cells.