'The Office' spinoff casts Dwight's brother

The Schrute family continues to grow in anticipation of a possible "Office" spinoff.

The latest addition to the clan in "The Farm" -- the working title for the spinoff -- is Thomas Middleditch, who will play Dwight's (Rainn Wilson) younger brother Jeb. As described, he's very different from Dwight -- he has engaged in all kinds of odd and unsuccessful ventures, including worm farming and sasquatch hunting and, when audiences meet him, runs a pot farm in California.

He joins Majandra Delfino and Blake Garrett in the cast of the spinoff, which will air as an episode of "The Office" this season.

Middleditch is a member of the Upright Citizens Brigade comedy troupe and can currently be seen in "The Campaign." He's also guest-starred on "The League" for FX and has a role in Josh Schwartz's upcoming movie "Fun Size."