There are many ways to fly. Characters of some races possess an innate ability to fly for certain lengths of time. Characters of some classes may learn to levitate, to cast Fly on both themselves and others, or both. Even characters without such skills may consume certain objects like potions to make themselves fly temporarily. And some gear (like griffon wings bracers) may cause either characters or mobs that wear it to fly until they remove it. Some mobs may also have a "flag" that causes them to fly permanently unless characters cast a spell like Earthbind on them.