Queen Elsa (Once Upon a Time)

Queen Elsa is the main antagonist of the first two episodes of the fourth season of ABC's"Once Upon a Time". Elsa comes to Storybrooke accidentally through a portal, and with the belief that the townspeople have done something to Anna, she traps them inside with an ice barrier and unleashes a snow monster upon them. However, once Elsa realizes they had nothing to do with her sister, she turns to their side and becomes a protagonist. With Elsa leaving the role behind, the true antagonist reveals herself.