Arex

Arex is a fictional alien and a supporting character featured in the Star Trek multimedia franchise. He made regular appearances on Star Trek: The Animated Series between 1973 and 1974 and was voiced by actor James Doohan.

Overview
Arex was an Edosian and a member of the Federation Starfleet. Arex served aboard the USS Enterprise in the year 2269 as the ship's navigator, and held the rank of Lieutenant. He replaced Pavel Chekov as a member of the bridge crew during the last two years of the Enterprise' s five-year mission.