Credit: The CW

Another Vampire Diaries alum is joining The CW’s Supernatural spin-off, Supernatural: Tribes. Former TVD star Stephen Martines — who played bad guy Frederick in Season 1 — has joined the cast, reports E! Online. The spin-off will follow the supernatural underbelly of Chicago and the monster families who fight for control of the city.

Supernatural: Tribes has already landed two former TVD stars: fan favorite Nathaniel Buzolic, who played Original vampire, Kol, and Pretty Little Liars star Sean Faris, who portrayed washed-up jock-turned-vampire Ben on Season 1 of the hit CW series. In the spin-off, Nathaniel will portray David Hayden, a shapeshifter from one of Chicago's ruling monster families who has denounced his monster heritage and has been living as human for a long time. But he returns to the supernatural world after a tragedy.

Meanwhile, Sean has landed the lead in the highly anticipated show and will play Julian Durant, a werewolf from a wealthy family of lycanthropes that is at odds with the Hayden family.

As for Stephen, he will take on the role of Detective Freddie Costa, a crooked Chicago cop who serves as a mentor to newly-minted hunter Ennis (Lucian Laviscount), but is secretly on the payroll of one of the city's most powerful supernatural monster families.

Supernatural: Tribes' cast will be introduced in Episode 20 (“Tribes”) of Supernatural this season, set to air on April 29. The episode will serve as a backdoor pilot for the series, similarly to how the hit Vampire Diaries spin-off, The Originals, launched last Spring.  

Are you excited for Supernatural: Tribes? With such a hot cast, you can sign us up! Hit the comments with your reactions.

Catch the next episode of The Vampire Diaries on Thursday, March 6 at 8 p.m. ET on the CW.

Crystal Bell is an editor at Wetpaint Entertainment and our resident fangirl for all things The Vampire Diaries. Follow her on Twitter and Google+!