"I enjoy that look of confusion when an inferior being meets a higher power." - Scourge in Rise of the Beasts
Scourge was originally created from the parts of discarded Decepticons by Unicron according to the story of The Transformers: the Movie. He became known as the leader of the Sweeps and as a ruthless hunter. He is usually depicted as somewhat of an arrogant character.
In the RID story of 2000-2001, Scourge was subject to a bit of an identity crisis as he originally was made to be an Autobot, but Megatron eventually stole a protoform and infused it with part of his spark to re-create Scourge as a Decepticon. He battles internally for most of the series as to where his true allegiance should align itself.
In the Cybertron story, Scourge is the powerful leader of the Jungle Planet and again deals with a bit of a loyalty issue. After fighting alongside Megatron, Scourge eventually, although reluctantly at first aligned himself with the Autobots. The story ended with him leading the Jungle Planet in what he called "a new era of peace".
In Rise of the Beasts, Scourge is a cold-hearted Terrorcon who is the most fearsome trophy hunter in the universe. He is a ruthless, cunning, treacherous, cruel, and incredibly powerful player that should be avoided at any cost. He commands the Terrorcons on the mission of destruction they have carried out for thousands of years across thousands of worlds, leaving nothing but chaos and ruin in their wake. Helping him in his relentless pursuit, Scourge keeps a collection of six-legged Sweeps - mechanical insectoids he can send out to sniff out his prey.