Another Lost actor is joining the cast of Once Upon a Time during the second half of season 3.

Rebecca Mader, who played the red-headed Charlotte on Lost, will be playing the next "big bad" villain in Once Upon a Time, according to a new report by E!Online. The actress will be playing a big villain whose identity is being kept secret.

While the identity of the villain is being kept secret, the report may have offered up a possible clue. The report mentions the phrase "long road of adventures," which may allude to the Yellow Brick Road in The Wizard of Oz. This could indicate that Mader will be playing the Wicked Witch of the West, a character that has not yet appeared on Once Upon a Time.

The identity of Mader's character will officially be revealed in the promo following the midseason finale on Dec. 15, according to the report. The character is said to be a major one in the latter half of season 3.

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The news of Mader's casting comes a day after The Originals actress Alexandra Metz was announced to be playing Rapunzel in the fantasy series. Enstars previously reported that Metz will be appearing as Rapunzel in the 14th episode of season 3, which will air at some point after the midseason premiere on Mar. 9, 2014.

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

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Watch a trailer for the next episode of Once Upon a Time here:

Tags: Once Upon A Time Once Upon A Time Season 3 Spoilers