Former "Saturday Night Live" cast member and consummate mockumentary pioneer Christopher Guest will return to television for a new comedy series on HBO.

The cable network on Thursday announced that it has placed a straight-to-series order for Guest's "Family Tree," a single-camera comedy about an unemployed 30-year-old who receives a mysterious box from his great aunt and begins to uncover a multitude of family secrets. "Bridesmaids" star Chris O'Dowd will play the lead with other cast members to be announced.

The series will be decidedly Guestian, employing the pseudo-documentary format that Guest help popularize with director Rob Reiner in 1984's "This Is Spinal Tap." Guest created "Family Tree" with the British actor Jim Piddock, a longtime collaborator, and he and Piddock will make appearances in the series as well.

HBO ordered eight episodes of "Family Tree," which will be produced by Guest and Piddock, along with NBC Universal International (Nasdaq: CMCSA), Lucky Giant Productions and "Spinal Tap" producer Karen Murphy.

Guest's break through film, "This Is Spinal Tap," was only a modest success at the box office. However, it was widely praised by critics and earned Guest a cult following upon its release on video. In 2002, the Library of Congress added it to the National Film Registry, a list of archived films deemed to be "culturally significant." After "Spinal Tap," Guest went on to direct a string of comedies -- including "Waiting for Guffman," "Best in Show," and "A Mighty Wind" -- utilizing the same blend of handheld camerawork and heavily improvised dialogue. The filmmaker's traditional narrative films have not been as successful, however. "Almost Heroes," a 1998 comedy starring Chris Farley and Matthew Perry as a pair of bumbling explorers competing with Lewis and Clark, took in a paltry $6 million at the box office, according to Box Office Mojo.  

Guest's "Family Tree" is the newest addition to HBO's increasingly comedy-heavy slate. The series will join other comic series on the network, which include "Girls," "Veep" and "Enlightened," and "Eastbound & Down."

No word yet on when the series will premiere.