The Monitors are a group of fictional comic book characters, who appear in books published by DC Comics. They are based on the Monitor and the Anti-Monitor, two characters created by comic book writer Marv Wolfman and comic artist George Pérez as the main characters of DC Comics' Crisis on Infinite Earths limited series. They are a group that watches all aspects of the Multiverse, past and present. Most importantly, they seek to prevent crossovers between the universes, as was common before "". The Monitors first appeared in Brave New World.