"Agents of SHIELD" will return for its second season with the addition of Adrianne Palicki as Bobbi Morse, codenamed Mockingbird. The SHIELD agent will apparently clash heads with Director Phil Coulson. Skye's father will also be introduced.

According to Hollywood Reporter, Palicki will be playing the role of comic character Bobbi Morse, a Marvel superspy who will be guest starring in the fifth episode and could possibly return for more episodes. Bobbi Morse is better known by comic book fans as Mockingbird.

It remains to be seen whether Palicki's character will be an ally to the team led by Coulson (Clark Gregg), but IB Times says that Morse will be clashing heads with the new Director. This is apparently similar with her comic book timeline. According to IB Times, in the comics Morse clashed not with Coulson, but with Clint Barton, better known as Hawk Eye, before marrying her.

Hollywood Reporter says that Mockingbird's involvement with the show was first hinted at back in July at the San Diego Comic-Con, where Patton Oswalt, who played Billy and Sam Koenig in season one, suggested the appearance.

Palicki is not a neophyte in the comic book world, adds Hollywood Reporter. The article says, "She famously played Wonder Woman for DC in NBC's David E. Kelley pilot and Nadia in the WB pilot Aquaman." IB Times also recalls Palicki starring in "Smallville" as a Kryptonian Supergirl. Also according to the article, Palicki is a "hardcore comic fan outside of her acting career." The actor apparently has a Supergirl tattoo.

Aside from Palicki, Hollywood Reporter also revealed other guest stars. Kyle MacLachlan will be introduced as the father of Skye (Lucy Bennet). Lucy Lawless will also guest as a veteran agent named Isabelle Hartly, and Henry Simmons is cast as an agent named Amphonso Mackenzie.  Simon Kassianides will also be guesting as Bakshi, while Reed Diamond has landed the role of Daniel Whitehall, also known as the Hydra villain Kraken.

Meanwhile, Entertainment Weekly adds that ABC is slowly building up interest for the return of the show via the unveiling of a billboard for "Agents of SHIELD" featuring the alien equation viewers have seen in season one. "Agents of SHIELD" will return on September 23.