Monitor was once a regular reptile, who gained intelligence when he drank a sample of Curt Connors' DNA which leaked into the sewer. Monitor and his companions Gila and Gecko also inherited The Lizard's superhuman strength. They kidnapped Connors, claiming that he was their 'father', and planned to take over the world and populate it with intelligent reptiles like them. When Mary Jane Watson, Margaret Connors and Debra Whitman arrived, Monitor was returned to normal along with the other lizards.
- The character was voiced by Rodney Saulsberry in Spider-Man: The Animated Series.