Dr. Malignus is a super villain based in New York City. He has no powers, but was able to develop tiny robotic bugs that allow him to control the minds of other people.
In the 2003 series, Dr. Malignus first appears in The Unconvincing Turtle Titan. In this episode, he is able to control the actions of various people by using little robotic bugs that he created. When Silver Sentry came to investigate, he too was taken over by Dr. Malignus. Michelangelo was able to return Silver Sentry back to normal, and the two defeated Dr. Malignus.