WARNING: The following contains spoilers for The Falcon and the Winter Soldier Episode 5, "Truth," now streaming on Disney+.

If you haven't seen the latest episode of The Falcon and the Winter Soldier on Disney+, those on social media have taken the liberty of preemptively filling fans in on who Episode 5's big came was.

In "Truth," there's a surprise cameo from Veep and Seinfeld star Julia Louis-Dreyfus. Her character introduces herself as Valentina Allegra de la Fontaine before quickly course-correcting and adding Contessa Valentina Allegra de la Fontaine. Marvel Comics fans will immediately recognize this as the alias of Madame Hydra, which is currently trending on Twitter along with Julia Louis-Dreyfus.

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Created by Jim Steranko, Contessa Valentina Allegra de la Fontaine made her debut in 1967's Strange Tales #159. Once a high-ranking member of S.H.I.E.L.D. (and a former love interest of Nick Fury), Valentina would secretly join the villainous Hydra and adopt the moniker of Madame Hydra, taking over the mantle from Ophelia Sarkissian/Viper, whom she killed.

It was recently reported that Episode 5 of The Falcon and the Winter Soldier would feature the Marvel Cinematic Universe debut of a major Marvel Comics character. "There are characters in our series who I would love to see partnered with like -- it's a very, very grounded character -- partnered with one of the big world-shakers like Thor or someone like that," series creator Malcolm Spellman said. "The personality is so strong, it's the episode five character. I'd love to see that character with Thor."

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It didn't take long for these comments from Spellman to begin fueling fan theories about who could appear in the series. In fact, the subsequent tease about a possible Chris Evans cameo even seemingly resulted in some wires being crossed, as fans were suddenly predicting established MCU characters such as Steve Rogers or even Black Panther might show up. Of course, the latter also stemmed from the surprise appearance by the Dora Milaje, who are the sworn protectors of Wakanda.

Directed by Kari Skogland, The Falcon and the Winter Soldier stars Anthony Mackie, Sebastian Stan, Emily VanCamp, Wyatt Russell, Noah Mills, Carl Lumbly and Daniel Brühl. New episodes debut Fridays on Disney+.

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Source: Twitter