Doctor M is a character and main antagonist from Sly 3: Honor Among Thieves.
Dr. M was once part of a team with Sly's father, where he was the brains of the group, similar to Bentley. However, he thought that Sly's father was holding him back, so he betrayed the team and went on his own. His main goal was to steal the Cooper fortune, which was located on Kaine Island.
He tried repeatedly to break into the Cooper Vault on Kaine Island, but was unsuccessful. This led him to eventually buy the island, as well as the deed to it, where he constructed a fortress around the vault. He also created a bunch of hybrid beasts to help guard the island.
Dr. M has shown to be extremely intelligent and even ruthless, going as far to kill one of his own guards (poisoning him), for making a simple mistake. He also thought highly of himself, although he showed admiration for those he found to be his equal, such as Bentley, as well as even complimenting those he felt were beneath him, such as Murray, who he thought was a "caveman."
He did manage to steal Sly's cane, but lost it later on, although he managed to slip a tracking device on it. He used this to track Sly's movements through the Cooper Vault, where he pursued him into the innermost chamber. It was here that he fought with Sly and was defeated by him until Carmelita showed up. Dr. M took a shot at her, which Sly jumped in front of to take the hit. He was finished off by Carmelita and was killed when the Cooper Vault collapsed on him, as he refused to leave.
