M.O.M
As the multi-tasking director of "The Center", she oversees the investigation of paranormal activities throughout the world. Martin's amazing capabilities make him one of M.O.M.'s favorite agents - if 'favorite' is meant by the agent that she least likes to have appear in her office. Her real name is unknown, though she has used the alias Ms. Olivia Mandell in episode "Web Of The Spider Creature", which is derived from her initials of M.O.M. Before working at the center she used to drive an ice cream truck. Serious and uncompromising, she has to deal with Martin blowing up just about every piece of gadgetry she is working on whenever he appears for a debriefing in her office. Despite her typically dry sense of humor, she is actually quite- as Billy says- "a real party animal." When she was an agent, her first ever creature captured was Gastromo.
M.O.M is often seen as being harsh and authoritative with her employees, especially Martin Mystery. Nevertheless, M.O.M is shown to care for her agents and have a strong sense of responsibility. It is often hinted throughout the show that M.O.M might be somewhat of a workaholic by the fact that she was forced to take up a hobby and has never taken a sick day. Her life outside of the Center is also unknown.
In the crossover episode of Totally Spies! titled "Totally Mystery Much?", M.O.M. is shown to have a history with the spies' boss Jerry that appears to have romantic undertones much to the spies and Martin's displeasure. In this episode, it was revealed that the initials M.O.M. stand for "Mystery Organization Manager". .
As of the last episode, M.O.M was seen being forced to take a two week seminar to correct her personality problems. As a result, Billy was left in charge of the Center while she was gone. It is unknown if she returns as the Head of the Center.