Sentreye

A Sentrye is a Luminoth security drone. They appear to be blue circles embedded into the rock of Aether. They are, as the name suggests, sentries for the Luminoth. They also have a dark counterpart, the corrupted sentrye.

Name
The name "Sentreye" comes from a portmantue of the words "Sentry" and "eye". This perfectly describes them, as they are sentry eyes.