The CW's Supergirl casts Nicole Maines as Nia Nal aka. Dreamer as a series regular in season 4; she becomes TV's first transgender superhero. Supergirl originally started out as a television series on CBS, but after the show's first season didn't garner the ratings the network wanted, it moved over to The CW for season 2. Since then, Supergirl has become more immersed in the Arrowverse - though it takes place on a different Earth in the multiverse - while still maintaining what worked about the female-lead superhero series from the start. Supergirl wrapped up its third season earlier this year and will return for season 4 later this year, reing Arrow, The Flash, Legends of Tomorrow and Black Lightning.

The CW's lineup of superhero shows has become a beacon of inclusivity among superhero media, with Legends of Tomorrow featuring an ensemble cast of men and women from all walks of life - including live-action media's first Muslim superhero with TV's first transgender superhero.

Related: Supergirl Season 4 Inspired By DC's Superman: Red Son

As announced at the Comic-Con for Supergirl, actress Nicole Maines s the series in season 4 as Nia Nal aka. Dreamer. The character of Nia is described as "a soulful young transgender woman with a fierce drive to protect others." Her season 4 arc will see Nia evolve into the superhero known as Dreamer, which will run parallel to Kara's own journey to find her way back to Supergirl following the events of season 3.

Nicole Maines Royal Pains

The character name of Nia Nal will likely sound familiar to fans of the DC Comics, since there is a Nura Nal who was introduced in 1964, making her debut in Adventure Comics #317. Nura is the superhero known as Dream Girl (who at one point in the '90s, goes by the name Dreamer), a member of the Legion of Super-Heroes. Nura Nal comes from the planet Naltor, and possesses a precognitive ability by seeing visions of the future through her dreams. It seems Nia Nal will be a spin on this character from the comics, but it's unclear how much of Nura Nal's origin will be adapted to Supergirl. The show hasn't shied away from introducing various alien species, and Nia may be an refugee on Earth like many other characters on the show.

As for Maines, her name may be familiar to some for her involvement in the 2013 Doe v. Clency landmark case in which the Maine Supreme Court ruled that it's unlawful for a school to deny transgender students from using the bathroom of their gender. Further, the actress has appeared in the USA's Royal Pains, while Maines herself was featured in the HBO documentary The Trans List.

Considering Supergirl saw the Supergirl when the show returns later this year.

Next: All the DC Movies and TV Shows Streaming on DC Universe