ABC has released a new sneak peek clip of the next episode of Once Upon a Time, teasing the big showdown between Zelena (Rebecca Mader) and Regina (Lana Parrilla).

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The clip, set to air in the episode It's Not Easy Being Green, features the various citizens of Storybrooke gathering together. Among this group are Emma (Jennifer Morrison), Snow (Ginnifer Goodwin), Charming (Josh Dallas) and Tinker Bell (Rose McIver), who worry that Regina might not show up for the big showdown.

Zelena makes her presence known within the crowd with a dramatic entrance, arriving with Rumplestiltskin (Robert Carlyle). She boasts that Regina must be here in five minutes or else she will "let the Dark One off his leash," referring to poor Rumple.

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On cue, Regina makes a dramatic entrance of her own, throwing in a quick jab: "Didn't anyone tell you? Black is my color," she says in reference to Zelena's all-black attire.

The two seem ready to battle as the clip cuts off, teasing a huge showdown about to go down right in the middle of town.

This episode of Once Upon a Time is centered on Zelena and her alter ego, the Wicked Witch. Once co-creator Edward Kitsis told TV Guide recently that viewers will be meeting many important people in Zelena's life.

"You will meet Zelena's father and find out the answer to who the Wizard is this weekend," he said.

Once Upon a Time season 3 airs Sundays at 8 p.m. on ABC.

Watch the sneak peek for the next episode of Once Upon a Time below:

Tags: Once Upon A Time television ABC