The Mor-Taxans are short aliens. They have pink-colored skin with deep purple viens that show. They have long, three-fingered arms and each finger has a suction cup. Mor-Taxans also have a third arm that reaches out from their chest, commonly not shown and only used to kill humans.
The entire Mor-Taxan race cannot survive on Earth for long before the planet's bacteria cause the aliens to go into a hibernation, but doesn't kill them.
Mor-Taxans have the ability to posess the bodies of human beings, killing the human and fitting into their body. However, their disguise as a human can only last for 24 hours before they must kill another human to assume a new body.