The Mentors are a sapient spacefaring civilization of legless amphibianoid beings from the planet Thoros Beta. These short creatures have greenish membranous skin, a crested humanoid head on top of a robust torso, a pair of webbed arms and a short flexible tail. Despite surviving on land, as they possess both gills and lungs in their chests, they need to keep their bodies adequately moist. As youngsters they have poisonous spikes on their tails, but these are later lost with age. They also have an acute sense of hearing, can live hundreds of years and are known to make a gargling-like sound when they laugh.
The Mentor civilization is capitalistically aggressive, and they are known to intimate and dominate smaller worlds by economical means, having no qualms about lying, cheating and deceiving to benefit themselves in the market. Their homeworld of Thoros Beta has vast pink oceans and a green-hued sky, and the Mentors seem to build their settlements mostly underground. They have completely enslaved the humanoid natives of their sister planet Thoros Alpha and use them as workers in their cities. The Mentors are also religious to some extent, worshiping an entity known as Morgo.