The Guardian is an enemy robot found in 2300 A.D. in Chrono Trigger. It is the "boss" enemy the player must defeat in Arris Dome. The Guardian robot also has two Bits helping in the battle.
Beyond the Ruins
In trying to help the people of Arris Dome, Crono, Marle and Lucca find themselves battling the Guardian and two Bits so they can reach the refrigeration area. The Guardian robot is ultimately defeated and Crono is allowed to pass.