[UPDATE: Owain Yeoman's casting in the Supergirl pilot has been confirmed!]
CBS' Supergirl series from Greg Berlanti (The Flash, Arrow) and Ali Adler (The New Normal, Glee) is currently in the midst of production - adding another series to the ever-growing DC TV universe. While not much is known about the series other than the basic plot synopsis, cast, and creative team involved - rumors of certain iconic comic book heroes already existing in the universe continue to point towards Supergirl possibly being the largest DC TV show in scale to date.
It is still unknown whether or not this series will exist in the same universe as The Flash and Arrow - if it does, then fans will definitely be in for an interesting addition to the tone and style of the previously mentioned shows. After all, there has already been confirmation that the series won't be shying away from Kara's alien origins; not to mention the rumors about super-powered/alien villains having already been cast in the series.
io9 has recently reported that The Mentalist star Owain Yeoman has been cast in the series and will be playing the DC comic book character, Vartox. While nothing is official as of right now, Yeoman's name can be added to the other list of comic book heroes and villains rumored to be making appearances in the CBS series. The character has also mostly interacted with Superman whenever he's shown up in the comics, so this could hint even more towards the Man of Steel having a role in the series.
UPDATE: CBR has now confirmed with WBTV that Yeoman is, in fact, playing Vartox in the Supergirl pilot.
Vartox is a character from the comics that is a friend (and sometimes foe) to Superman. He is from the planet Valeron, but when his home planet is destroyed, Vartox comes to Earth as a replacement home and at one point falls in love with Lana Lang. His powers are similar and equal to Superman's and his appearance is said to be an homage to Sean Connery's character Zed from the 1974 film, Zardoz.
Supergirl certainly seems to be garnering an interesting cast of actors and characters for itself right off the bat (assuming this casting is true) with the previously mentioned alien characters and now an obscure character like Vartox - it doesn't seem like the creative team is shying away from going deep into the comic book lore with this one.
Yeoman is a TV veteran at this point with roles in successful shows like The Mentalist and Extant, so it should be a welcome sight for TV fans to see him pop up in Supergirl at some point (if confirmed) - and while most are claiming Vartox as a villain in the series, the original report referred to Vartox as a hero, so it looks like his character could go either way in the show.
CBS' Supergirl is currently in production.
Update Source: CBR