The Thunder Megazord, also referred to as Mega Thunderzord or simply Megazord, is the Mighty Morphin Power Rangers’ second Megazord formation, created by merging the five Thunderzords: the Red Dragon, Lion, Unicorn, Griffin and Firebird Thunderzord.
When Lord Zedd came to Earth, he created Pirantishead, who quickly used his powers to take control of the Tyrannosaurus Dinozord and the Dragonzord while freezing the other Dinozords. Zordon and Alpha 5 began work on the creation of the Thunderzords. By using the Dinozords as templates, they would use the “power of thunder” to transform the Dinozords into the Thunderzords. The Rangers first had to reclaim their Dinozords from Pirantishead, which they did after a struggle.