Maureen Brown, also known as "Mo" and "Queen Maureen of the Dead," is an antagonist from The Mortal Instruments.
Maureen Brown was a young girl of fourteen years. She was a groupie of Simons rock band, and in addition, very obsessively in love with Simon. It went to the point that she almost stalked him. She secretly took pictures of him, and told everyone that he was her boyfriend.
After a performance of the band, she visited Simon behind the stage, but he was already a vampire at that time. As a young vampire, however, he did not have much control over his new shoots, and attacked them accidentally. Maureen was then saved by the werewolf Jordan, and Simon was horrified by what he had done.
However, Camille Belcourt believed that Maureen was Simon's girlfriend. She took her captive, and wrote to Simon a letter to come to them, otherwise shw would kill his girlfriend. Simon thought they meant Clary, Isabelle, or Maya, girls with whom he was a befriended. When he found out that they were all safe, he ignored the letter. The next day he learned that Maureen had been killed.
However, Camille Maureen had previously made an offer, namely that she could return as a vampire after she had killed her. Maureen accepted the offer, and later became a vampire. However, she became insane through the transformation into a vampire, and her love for Simon became even more obsessive.
After Lilith´s defeating, Maureen killed Camille and took over the leadership of the New York vampire clan. They allowed their members to kill every person they wanted, and they eventually murdered the humans unrestrained. Finally, she also had Simon kidnapped him to make her her "king", since she called herself a "queen" of the vampires. Some vampires of the clan were not happy with Maureen's rule, and one of them conspired with the werewolf Maya to lure Maureen into a trap. She brought her to drink her blood, which, however, had been spiked with holy water. When Maureen drank the blood, the holy water burnt her inwardly, and she was killed.
- Maureen was by the vampire of New York as a very vicious vampire queen rememberes.
- She was amazingly strong for a young vampire. She could kill Camille, who was a much older vampire (vampires in TMI are getting more and more powerful with age), and also had significantly more experience.
- Her obsession with Simon resembles the relationship of Akasha and Lestat in the books of Anne Rice. Another fact is that she forced Simon to wear similar clothes as Lestat.