Vladimir Propp

the villain, who struggles with the hero (formally known as the antagonist)

the donor,

the helper,

the Princess, a sought-for person (and/or her father), who exists as a goal and often recognizes and marries hero and/or punishes villain

the dispatcher,

the hero, who departs on a search (seeker-hero), reacts to the donor and weds

the false hero (or antihero or usurper), who claims to be the hero, often seeking and reacting like a real hero (ie by trying to marry the princess)