VIDEO: Watch 2 Clips from Sunday's ONCE UPON A TIME

On the next episode of ABC's ONCE UPON A TIME IN WONDERLAND titled  "It's Not Easy Being Green". with Rumplestiltskin as her slave, Zelena challenges Regina to a fight to the death and shocks the Evil queen with the reveal of their familial connection, and the town lays Neal to rest. Meanwhile, back in the past in the land of Oz, a jealous Zelena asks the Wizard to send her to Fairy Tale Land after discovering that she has a sister, Regina, and that Rumplestiltskin is training her to become a powerful force to be reckoned with.

The episode airs SUNDAY, APRIL 6 (8:00-9:00 p.m., ET) on the ABC Television Network. Watch two preview clips below!

"Once Upon a Time" stars Ginnifer Goodwin as Snow White/Mary Margaret, Jennifer Morrison as Emma Swan, Lana Parrilla as the Evil Queen/Regina, Josh Dallas as Prince Charming/David, Emilie de Ravin as Belle, Colin O'Donoghue as Hook, Michael Raymond-James as Baelfire/Neal Cassidy, Jared S. Gilmore as Henry Mills and Robert Carlyle as Rumplestiltskin/Mr. Gold.

Guest starring are Keegan Connor Tracy as Blue Fairy/Mother Superior, Beverley Elliott as Granny, Rebecca Mader as Zelena, David-Paul Grove as Doc, Gabe Khouth as Sneezy/Mr. Clark, Christopher Gorham as Walsh, Sean Maguire as Robin Hood, Rose McIver as Tinker Bell, Adrian Hough as woodcutter and Maria Marlow as wife.

"It's Not Easy Being Green" was written by Andrew Chambliss and directed by Mario Van Peebles.

"Once Upon a Time" is broadcast in 720 Progressive (720P), ABC's selected HDTV format with a 5.1 channel surround sound. This program carries a TV-PG,V parental guideline.

For more information on "Once Upon a Time," visit ABC.com/Once

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