Power Rangers Megazords

In the universe of the television series Power Rangers, Zords are colossal mechanical or bio-mechanical robots. When monsters grow to incredible sizes, the only way the Power Rangers can fight them is by summoning and piloting these enormous war machines. Usually this will happen towards the end of every episode. 

The Zords come in many different forms. Some take the form of animals, both current, mythical, and extinct. Some of them are humanoid in appearance, such as the Shogunzords and Super Zeo Zords. Others simply look like giant vehicles or other traditional machines (examples include the Turbozords, Time Flyers, and Delta Runners). When the individual Zords are inadequate for the task, they can join together into a more powerful, humanoid robot called a Megazord. 

Starting with Season 2 and the Tigerzord, one Ranger can possess a Zord that becomes its own Megazord. Examples include the Q-Rexand the Omegamax Cycle. 

Every season of Power Rangers from Mighty Morphin Power Rangers onwards saw a new set of Zords being deployed by the current Rangers. Each set is based on the Mechafrom the connected Super Sentai series. This change of Zords occurred even before the yearly costume change to match the equivalent Sentai series. 

Although it is never stated in the series, it is assumed that the Zords are named after Zordon, the first mentor of the Power Rangers. This is seemingly evidenced in the pilot episode, where Zordon was named Zoltar, and the Zords were called "droids." 

It's been a tradition for the primary Megazords to wield swords or other melee weapons while the rest would have blasters, laser guns, cannons or other long-range weapons to fight with. On occasion, sometimes a Ranger will use another Ranger's Zord, and the Rangers will sometimes pilot their Zords while not morphed.

http://powerrangers.wikia.com/wiki/Category:Zords