Supernatural spinoff 'Tribes' casts 'Heroes' star Danielle Savre and 'Burn Notice' star Stephen Martines

The Supernatural spinoff subtitled Tribes has added two more members to its cast in Danielle Savre (Heroes) and Stephen Martines (Burn Notice, The Closer).

Savre will play Margo, the head of a family of shapeshifters. The character is an "ex-punk rocker-turned-corporate professional who feels threatened only by the return of her prodigal brother David," according to TVLine. Nathaniel Buzolic of The Originals plays David.

Martines will portray Detective Freddie Costa, "a world-weary" cop who acts as a mentor to new hunter Ennis Roth (played by Episodes' Lucien Laviscount) and is also on the payroll of one of the monster families.

The show made another casting decision earlier this week in Sean Faris, who will play Julian Durant, the son in a wealthy family of werewolves who harbors hatred for the shapeshifters of the Hayden family, according to TVLine,

Faris currently has a recurring role on Pretty Little Liars as Officer Gabriel Holbrook and has previously ventured into the supernatural genre with a role as vampire Ben on Season 1 of fellow CW series The Vampire Diaries. He has also starred on Reunion and Life As We Know It.

The characters will all appear in the 20^th episode of Supernatural's current ninth season, which will serve as a backdoor pilot for the show.

Tribes has been described as a "sweeping drama about the various mafia-esque monster families that unknowingly-to-humans 'run' the underbelly of Chicago and who are being tracked by a newly-minted Hunter who's trying to stop them and rid Chicago of anything or anyone supernatural."

What do you think of the casting choices for Supernatural: Tribes thus far? Let us know in the comments below.