Dairen'oh (大連王) is the central combining robo of Gosei Sentai Dairanger (1993), formed from the team's five Mythical Chi Beasts (Kidenjū): the dragon Ryuseioh, the lion Star-Shishi, the pegasus Star-Tenma, the qilin Star-Kirin, and the phoenix Star-Houou. Ryuseioh makes up the core of the robot while the other four beasts attach to it as armor and limbs, and the colossus is piloted by all five Dairangers together. Western collectors know it as the Thunder Megazord: in Mighty Morphin Power Rangers Season 2 it became the centerpiece of the Thunderzords, succeeding the first season's Dino Megazord.

A lovely quirk: Ryuseioh doesn't have to wait for the full combination – via "Warrior Change" it can take the field on its own as the humanoid Warrior Ryuseioh (Mythical Chi Warrior RyuseiOh). As Dairen'oh it wields two main weapons, the Great King Sword (Daiō-Ken) and the Dai Javelin, whose tip is formed from the tail of the phoenix Star-Houou. And it scales up further: when Won Tiger, the beast of the sixth warrior Kibaranger, takes the core in place of Ryuseioh, it combines with those same four limb beasts to form the even mightier Kiba Daioh.

The original DX toy, Bandai's DX Dairen'oh (Japan, 1993), is a classic 90s chogokin with a satisfying amount of die-cast, plenty of chunky "brick" charm, a chrome sword, and clean paint and stickers. It shipped with two mini figures of each of the five Dairangers – a detail that keeps the Japanese release sought after among collectors to this day.

The US version, Bandai America's Thunder Megazord (1994), uses the same mold but arrives as a recolor with new decals: the lion head (Lion Thunderzord) was cast in black instead of green, the thighs were painted black, and the lion gained small rear legs that its Dairanger counterpart lacked. In place of the mini Dairangers it came with two mini figures of each core Power Ranger plus ten small Power Crystals. (Later reissues such as the 2016 Legacy edition, the 2018 Super Sentai Artisan, and the SMP model kit are separate collector entries.)