Beast

The Beast is a horrific Combiner from an alternate reality made up of the five Dinobots, who became an unstoppable killing machine who wiped out most of the Decepticons before turning on the Autobots, who were forced to destroy him. This reality would later be destroyed after suffering an attack from Unicron.

Trivia

 * While the Beast and the comic story in which he appeared were poorly received, the idea of a Dinobot Combiner remains popular with Third Party toy manufacturers.