It would not be out of line to call tonight’s “special” episode of “20/20” (7 p.m., ABC) “Hello/Goodbye.” It’s a farewell tribute to Regis Philbin, who is leaving his morning chat show Friday. “Regis Philbin: The Morning Maestro With Katie Couric” is also a re-reintroduction to Katie Couric, the former “Today” regular and “CBS Evening News” anchor who will return to daytime talk with “Katie,” an ABC-owned syndicated series that debuts in September 2012.

While tonight’s “20/20” hails Philbin’s morning show, few television talents have worked so much in late night, prime time and the post-breakfast hour. Philbin gained national recognition in the late 1960s as the sidekick to talk show host Joey Bishop, ABC’s answer to Johnny Carson. The host and Rat Pack member often made jokes at Philbin’s expense, and on at least one occasion Philbin fought back in an unscripted manner, giving Bishop’s low-rated show more attention than usual.

After years hosting local morning shows, Philbin was paired with Kathie Lee Gifford in the mid 1980s, and a morning institution was born. Gifford left in 2000, and Kelly Ripa joined Philbin in 2001. Over the course of so many mornings, Philbin has set the Guinness World Record for having spent the most hours before a television camera.

Some of those hours were spent in prime time on the American version of “Who Wants to Be a Millionaire,” a ratings blockbuster in 1999 that buoyed ABC’s fortunes and brought a spate of game shows to the evening hours.

In addition to his own shows, Philbin has been a regular on “Late Show With David Letterman” (10:35 p.m., CBS). And tonight is no exception. Expect Philbin to get under Letterman’s skin. John Fogerty also appears.

• A week before the big day, the folks from “Swamp People” gather for “Swampsgiving” (8 p.m., History), a celebration of wild turkey shooting, feral boar hunting and other Cajun delights, including squirrel, turtle, rabbit and something called gar, the largest freshwater fish in America. And what’s a little smoked gar without a frog leg chaser? The new series “Big Shrimpin'” (9 p.m., History) follows.

Tonight’s other highlights

• Another night of elimination on “The X Factor” (7 p.m., Fox).

• Dolphin advocates contend that the Navy’s sonar means death to the sea creatures in the 2010 drama “Beneath the Blue” (7 p.m., CW), starring Paul Wesley (“The Vampire Diaries”).

• The Cold War heats up on “Person of Interest” (8 p.m., CBS).

• Andy takes the staff on a field trip to Gettysburg on “The Office” (8 p.m., NBC).

• The death of a toy magnate on “Bones” (8 p.m., Fox).

• Amelia faces an intervention on a two-hour “Private Practice” (8 p.m., ABC).

• Michael helps the company on “Burn Notice” (8 p.m., USA).