Once Upon a Time may have debuted several Frozen characters in the Season 4 premiere Sunday night, but one scene unrelated Elsa (Georgina Haig) and Anna (Elizabeth Lail) has fans buzzing about a mysterious hat.

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Rumplestiltskin (Robert Carlyle) discovered a sparkly blue and purple hat in the Season 4 premiere of the series, and most Disney fans recognized it as the Sorcerer's hat, which is featured in the Disney classic Fantasia.

OAUT executive producer Edward Kitsis spoke with Entertainment Weekly about the inclusion of the hat and how it will come into play this season.

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"Yes, that's the Sorcerer's hat from Fantasia," Kitsis confirmed of the hat, adding, "We wanted to make the stars look real."

Rumple discovered the hat after vowing to become a better man at his son Neal's (Michael Raymond-James) grave and returned the dagger to Belle (Emile de Ravin).

"We're going to learn a lot more [about the hat]," Kitsis teased. "That's going to be part of something that we tell for a while, but clearly he wanted it badly enough that he was willing to go back on his pledge, because he can resist everything but temptation."

Apparently that hat does not belong to anyone Once Upon a Time fans have met before. Among the possible suggestions offered up in the comments section of the article were the magical wizard Merlin and Mickey Mouse himself.

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