The head of security on the planet Dramia, who serves an arrest warrant on Dr McCoy for mass murder and tries to stop Kirk from finding evidence in his defence.
Demos is the commander of the Dramen security police in the Animated Series episode Albatross.
As the Enterprise completes a delivery of medical supplies to Dramia, Demos presents a warrant charging McCoy with causing a plague that wiped out most of the colony on Dramia II, shortly after the doctor led an inoculation programme there nineteen years earlier. McCoy is jailed to await a trial whose outcome seems decided in advance.
When Kirk takes the Enterprise to Dramia II to investigate, Demos follows covertly in a one-man patrol ship. Kirk notices the pursuit, leaves the hangar doors invitingly open and takes Demos into custody as a stowaway, impounding his ship. Demos later falls ill with the returning plague himself and is cured by the antidote McCoy develops.