Marvel's Loki has been confirmed as gender fluid in promo for new Disney Plus series

• In a new promo for "Loki," a file on Loki can be seen that says Loki's sex is "FLUID."
• Loki is already gender fluid in the comics, as revealed in a 2014 issue.
• The MCU have been criticized for their lack of LGBTQ representation in the past.

Marvel has been building excitement for Disney Plus' "Loki" TV series by dropping sneak clips and previews in the lead-up to Wednesday's premiere.

The latest promo for the show may have been the most interesting yet, however, as it confirmed a detail about the beloved Marvel character played by Tom Hiddleston: Loki is gender fluid.

In the footage shared over the weekend, we see a conversation between Loki and Owen Wilson's Agent Mobius (part of the Time Variance Authority, or TVA).

At the beginning of the clip, we're given a glimpse of one of the TVA's files on Loki, which states that his sex is "FLUID."

Although this may come as a surprise to some, those familiar with the comic books will already know Loki has been gender-fluid in the comics for some time.

In the comic issue "Original Sin, #5.5," which was released in 2014, Odin refers to Loki as "my son and my daughter, and my child who is both."

The MCU has long been criticized for its lack of LGBTQ representation, especially when Marvel comics feature several characters on the LGBTQ spectrum - but this is a positive step forward for Marvel in terms of on-screen representation.

The character Valkyrie, who features in "Thor: Ragnarok" alongside Loki as well as in "Avengers: Endgame," has been confirmed as bisexual, while Marvel's "Eternals," out November 5, will feature the MCU's first openly gay superhero couple - played by Brian Tyree Henry and Haaz Sleiman.

It's been noted that Marvel's phase four, which includes "Loki," "Eternals," and the upcoming "Shang-Chi and the Legend of the Ten Rings," has notably embraced diversity more than previous phases. Marvel chief Kevin Feige told Variety in March that the shift can be partially attributed to the way the comics have been going for a while now.

"We're lucky that we have the comics to guide us. They have been relatively progressive over the decades for their time," Feige told Variety's Matt Donnelly. "The character lineup allows us - we're not creating full-cloth any of our characters, they've been in the comics for years - and we're finally able to tell those stories."

He continued: "Looking at the remarkably positive experiences we've had making sure that the room where it happens is not a room full of people that all look the same. When that's not the case, when there are people from various backgrounds and genders, stories are better."