First starting out as a rogue gang, ScourgeClan evolved into a clan. However they worship the Dark Forest not StarClan.

Their leader is a fierce tom named Wendigo, he eats other cats and doesn't like to be disobeyed. He's gathered cats of different clans that hated their clan or clanmates like Toxicheart of StormClan, Redblood of SkyClan, Articfrost of BlizzardClan, and Batwing of NightClan. Overtime Toxicheart and Redblood became two of his strongest warriors but neither became his second in command. Toxicheart still loved the she-cat who broke his heart and couldn't kill her when he had the chance and Redblood was too unstable for leadership.

After losing the territory they stole from StormClan, they moved to the other side of the forest. Where it suited them better. It was always dark over there, and it looked spooky. It's even rumored to be haunted, they hear moans and groans, and ghostly blue blurs are visible at some times.

This is the best example I could find. In case a picture is needed.