Obsidian and his consort Strika were the greatest generals in Cybertronian history, and two of Megatron's Vehicon generals in the second season of Beast Machines.

Remembered as a masterful strategist and tactician during a war with the Predacons sometimes after The Great War along with Strika, Obsidian was awakened by Megatron to assist in the defeat of the technorganics. Though he briefly played the part of a brain-washed machine similar to Tankor, his true intelligence was revealed when victory seemed inevitable, though the Maximals escaped shortly after. After participating in several battles he and Strika were launched into Cybertron's orbit shortly before the reformatting of Cybertron. In a cut scene, he and Stryka would have returned to Cybertron but refused reformatting as punishment for their transgressions.