In the "Beast Wars Shattered Glass" story arc the G1 Ultra Magnus travels to Shattered Glass prehistoric Earth with Prowl, Ironhide, Silverbolt, and Grimlock. Adopting a wooly mammoth beast mode in order to survive the raw Energon radiation, he adopts the identity "Ultra Mammoth", which he attributes to Grimlock. With their home universe destroyed, Mammoth and his team did battle with Megatron's force of Decepticons, who had adopted alternative means of survival. Joined by an alternate version of Depth Charge, the former Autobots took on a new identity as Maximals. After a number of battles with Megatron's similarly renamed Predacons, Ultra Magnus gained possession of the Origin Matrix.