Carolinus, The Green Wizard, is one of the four great wizards of magic. He dresses in a green robe to signify his connection with nature.
Carolinus' domain is nature and all its inhabitants. He displays affection toward natural creatures and presumably shows the same appreciation to the remainder of nature. He lives in a small cottage near a stream amidst a grassland, further illustrating his natural connection.
Carolinus exibits powers over the natural world. Drawing power from man's fascination and appreciation of nature, he uses incantations to exert magic to do his bidding. In the film, he is shown casting spells from turning wine into milk to combining Sir Peter with the young dragon Gorbash.