The Megans were a race persecuted by Humans during the 17th century, and they were accused of being warlocks
A warlock was the male equivalent of a witch, and similar to a wizard.
During their time on Earth, the Megans were persecuted by the native Humans, who accused them of being warlocks, wizards, and evil sorcerers.
This led to the genocide of many of their people after a series of witch trials in Salem, Massachusetts. (TAS: "The Magicks of Megas-Tu")