Beast Wars Neo: Super Lifeform Transformers(1999)

On a primitive planet with fauna similar to Terran dinosaurs and Ice Age critters, one of the angolmois energy capsules spread by the explosion of the Nemesis has affected the locals. A gang of evil dinosaurs have been transformed into Destrons, and a battered Lioconvoy is too injured to stop them. So he transfers his energy into a mammoth named Big, charging him with continuing the good fight.

(Source: Dave's Transformers Page).

Note: Includes nine manga chapters and three text stories.