As ABC's Once Upon a Time heads into its winter finale, its two show runners are previewing what's ahead for the second half of season 4, including more villains.

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The winter finale will tease the introduction of Cruella De Vil (Victoria Smurfit), Ursula (Merrin Dungey) and the return of Maleficent (Kristin Bauer van Straten), who now has a new look.

Regina (Lana Parrilla) and Emma (Jennifer Morrison) will be facing off against the trio of iconic villainesses, according to OUAT co-creators Edward Kitsis and Adam Horowitz.

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"I would say that the second half of the season, we're really going to test Regina in a way she's never been tested before," Kitsis said in a new interview with Entertainment Weekly.

Horowitz added that she is "going to have her hands full" while Kitsis quipped: "Dragons and tentacles and Dalmatians."

Kitsis said that the upcoming second half of the season would be much more "psychological" than anything else, and that Emma would have to team up with Regina.

"There's going to be a lot of agendas at play and mystery," Kitsis added. "Regina and Emma are going to be working together to try and defeat these three."

"They're great together," Horowitz teased.

The pair also suggested that there may even be more villains to come in the near to distant future.

Once Upon a Time airs Sundays at 8 p.m. ET/PT on ABC.

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

Tags: Once Upon A Time television ABC