King Mondo, also known as the Machine King, was the ruler of the Machine Empire. Driving Rita Repulsa and Lord Zedd off the moon, Mondo believed the Earth would be an easy conquest, but was shocked when his army of Cogs was repelled by the Power Ranger Zeo. He was intrigued by the Rangers, as his other conquests had been far too easy, and the Rangers proved to be formidable enemies. However, Mondo soon grew tired of the Rangers, and did everything he could to defeat them. Just as it seemed he would defeat the Rangers, the Gold Ranger arrived and foiled Mondo again. Mondo finally tired of fooling around and unearthed the ancient Sword of Damocles. He grew and battled the Rangers' new Super Zeo MegaZord, but was destroyed by the Zord's finishing attack. King Mondo was later rebuilt and returned to the throne, chasing away Prince Gasket and Archerina. When Jason began to lose the Gold Ranger Powers, Mondo tried to capture them for his own, coming into conflict with Rita and Zedd in the process. When the Gold Powers were returned to Trey, Mondo grew to giant size to seek his revenge, but was faced with giant-sized Zeo Rangers. Mondo was taken out by Tommy and Trey, and returned to the moon. There, he bid farewell to Zedd and Rita, who feigned leaving the Earth to the Machine Empire. Mondo was subsequently destroyed by their going away present. Rebult once again, King Mondo attended Dark Specter's conference on the Cimmerian Planet. Months later, he led the Machine Empire as it invaded both KO-35 and the Phantom Ranger's homeplanet, defeating Phantom and the Blue Senturion in the process. When Zordon's energy wave struck, King Mondo was reduced to a pile of sand, destroyed forever.