"Mystic Brothers" is an auxiliary mecha from the 34th Super Sentai series, Tensou Sentai Goseiger (2010). It belongs to the Gosei Headders — the transforming animal/object heads summoned by the Gosei Angels (the Goseiger team). The set comprises two parts: the ostrich-shaped Mystic Runner and the Egg Headder. Rather than a standalone main robot, it is add-on weaponry for the primary mecha Gosei Great and for the support robot Datas Hyper. In the US adaptation Power Rangers Megaforce (2013) the pair is called the "Mystic Brothers Zords" (Mystic Runnerzord and Egg Zord). Notably, it is the only ostrich-based mecha in Super Sentai history.

In battle the Mystic Runner kicks the egg at enemies like a soccer ball and fires energy bolts from its beak. When combined with Gosei Great, the Mystic Runner mounts on the left shoulder while the Egg Headder splits into two halves to form flail-type weapons on the left side. Attached to Datas Hyper it instead serves as a helicopter pack. Its finishing move, the "Mystic Strike," seals the enemy inside the egg, which reopens to trap and destroy the target within a bubble.

The DX toy was released in 2010 by Bandai (Japan) within the Gosei Headder line as the "DX Mystic Brother Set." It is a compact add-on set made mostly of plastic; like the other small auxiliary Headders, it contains virtually no die-cast. The Mystic Runner head opens up and plugs onto Gosei Great or Datas via the standardized Gosei Headder peg connector, and the Egg Headder separates into two halves. It is not a large boxed megazord but an accessory for DX robots a collector already owns. A separate wide US retail release under the Megaforce line is uncertain, so collectors generally acquire the Japanese Bandai DX version.