Under the mask, they are played by Marti Matulis (Surgeon), Douglas Tait (Pathologist), and Caitlin Dechelle (Geneticist).
The Dread Doctors a trio of three scientists. They are only known by their titles, the surgeon, the pathologist, and the geneticist. While not much is yet to be known about these three, the doctors appear to be slightly out of phase with reality as their bodies blur constantly. They are also known for their experiments with hybrid creatures. The Surgeon is the "leader" of the crew as he speaks the most and the one who killed their first experiment seen on screen and injected a girl named Tracy Stewart.
The Doctors come to Beacon Hills to pursue their goal of resurrecting the Beast, using teenagers from the town as surrogates to recreate the werewolf. However, most of their experiments were deemed failures, wreaking havoc on Beacon Hills as scientifically-created supernatural creatures called Chimeras. Their efforts have been hampered by the presence of Scott McCall's pack which has tried its best to find and stop the Doctors before they can kill too many of their fellow students from Beacon Hills High School.
Eventually, the pack gains a lead when Sheriff Stilinski and Melissa McCall discover that all Chimeras were already genetic Chimeras before the Doctors started experimenting on them (i.e. they possessed two sets of DNA, one their own, the other coming from a donor for a medical purpose). However, most of the Chimeras were killed by the Doctors themselves once they were deemed failures. The Doctors' patience eventually paid off when they succeeded in recreating the Beast, which they have unleashed upon Beacon Hills. As the Beast has been rampaging Beacon Hills at nights, the Doctors have tried to keep its presence as secret as possible by hiding the bodies of its victims, until Chris and Gerard Argent discovered them. Only a few places in the world are safe from the Doctors such as Eichen House because of the high concentration of telluric currents on the site. These currents disrupt the electromagnetic pulses from which the Doctors draw their power. Eventually, the Doctors succeeded in their goal of recreating the Beast, but as the cost of their own lives as they eventually confronted the werewolf.
The Surgeon is the "leader" of the Dread Doctors. His identity is revealed to be Marcel, the friend of Sebastian Valet.
The Pathologist is usually the fighter of the three. He is almost always seen at the Surgeon's side.
The Geneticist is the female Dread Doctor.