Megatron Beast is the main antagonist in the anime series 'Beast Wars: Chou Seimeitai Transformers.' As the ruthless leader of the Predacons, he is cunning, ambitious, and fiercely intelligent, constantly devising schemes to defeat the Maximals and secure the future for his kind. His beast form is a powerful purple Tyrannosaurus Rex, which he uses to intimidate and overpower his enemies. Megatron Beast's leadership and strategic prowess make him a formidable foe and central figure in the conflict throughout the series.