The Outlaws are a group bandits that roam Avalon. They are usually looking to rob the traveling caravans or wagon trains of the Craft Masters transporting their art to Craft Fairs. Most Outlaws are mostly male, but some are female, including a woman who appears to be a second-in-command after their boss.
Their dangerous and nasty leader, Civello (or Cirello, as his name is also written in the scripts), works with the series' villainess, Lady Kale. Kale too is an outlaw by status (and so "no longer bound by the laws of Avalon"), and is often described as "Outlaw Princess" in the season one scripts.
Civello and his gang are featured in two episodes through both seasons of the series. In "Badlands", Kale sets them to ambush a caravan in the Badlands so she can capture both Princess Gwenevere and Merlin's Key. When they capture Gwen, Kale just steals away their catch and flies off.
Later, in "Prince of the Forest", Kale hires them to capture or kill (with the help of a giant crossbow weapon) the mysterious Beast (Ian) in the Forests of Arden in order to get its Wizard Jewel for herself. It ends up with the enraged Beast completely trashing their camp and the Outlaws fleeing in fear.