The Lizard King was from the Q Foundation, just like Aztek
. The Lizard King was assigned as the second-in-command to Aztek's father, Emilio, who served the Foundation as the prior Aztek. When Emilio fell in love with a woman in America, the Foundation felt their mission compromised. They sent the Lizard King to kill Emilio, and to retrieve Emilio's son to raise him as the next Aztek.
Having trained all his life to be Aztek, the Lizard King felt that the current Aztek was unworthy. As a result, the Lizard King decided to take matters into his own hands. He created machines with human 'pilots' to capture Aztek. When that failed, he captured and tortured Aztek's girlfriend, Joy Page
When Aztek arrived, he was badly beaten by the Lizard King. The Lizard King took his helmet and prepared to become the new champion. However, he had not learned the mind-block techniques that allowed the user to overcome the stored minds in the helmet. They overwhelmed the Lizard King, killing him.