The Alpha Centaurians are a humanoid race with fine grey scales and other piscine adaptations (gills, webbed toes) that enable them to live underwater. Their government is a feudal one, organized into several small, independent kingdoms; their culture tends to be self-centered and dispassionate. They are native to Arima, the third planet orbiting Alpha Centauri A. Arima has water covering 95% of its surface, and its gravity and atmospheric thickness are both approximately twice that of Earth. They possess spacecraft capable of 85% lightspeed.
- They were first seen in Sub-Mariner #17 (Sep 1969).