Monsieur Mallah is the secondary antagonist of the fifth and final season of Teen Titans.
He was voiced by the late Glenn Shadix in the original series, who also played Brain in the same series.
Monsieur Mallah first appears in "Homecoming Part 1" and "Homecoming Part 2", where he first attacked the Doom Patrol. The Brotherhood of Evil's first plan was foiled by Beast Boy. The member of The Brotherhood of Evil gathered several villains from previous seasons, including a few new villains to plot revenge and capture the Teen Titans, even new heroes.
In the episode "Hide And Seek", Mallah was sent to kidnap Melvin, Teether, and Timmy, the three heroic kids that Raven was protecting. He attempts to get away in a vehicle armed with lasers, but Melvin's imaginary (but now visible) friend, Bobby the bear arrives to attack and defeat the villainous gorilla, forcing Mallah to retreat.
In the final battle in "Titans Together", Mallah attempts to get away with The Brain, but Robin and Beast Boy stop them just in time. Beast Boy finished him off and in the end, he was frozen along with the other frozen villains and his crew.