What do you get when you blend “American Idol” and “Star Search” with David Letterman’s “Stupid Pet Tricks”? A perfectly entertaining half-hour of television distraction called “Pet Star” (7 p.m., Animal Planet), with Mario Lopez (“Saved by the Bell”) as host. Each animal act — make that bird, reptile and crustacean act — will be judged by a panel of three notables, who, like Lopez, reside in the “where are they now?” subdivision of Celebrity Gulch.

Tonight’s “Pet Star” panel features Peter Scolari (“Bosom Buddies”), Lindsay Wagner (“Bionic Woman”) and Gena Lee Nolin (“Baywatch”). But don’t be too dazzled by the combined wattage of their celebrity — the real stars here are the critters.

After each performance, the contestants receive a grade from the judges. Scolari is quite witty, Nolin is a soft touch, and Wagner tends to agree with everyone else.

At the end of the show, the audience gets to pick a winner from the three top scorers. That creature and his or her human companion win a $2,500 prize and a trip to Hollywood, where they will compete for a $25,000 prize during a two-hour grand finale. That kind of loot buys a lot of kitty litter.

• Fans of the farfetched should not miss “Book of Days” (7 p.m., Pax), a supernatural TV movie with one of the oddest plots in recent memory. Danny (Wil Wheaton), a glum life insurance salesman, has a crisis of faith after his radiant bride is killed by a wayward pickup truck on their wedding day.

Did I mention that his gorgeous wife was an ex-nun? Or that his best man was a woman? Still prostrate with grief, he receives a peculiar package from a mysterious messenger played by Isaac Hayes.

Give “Days” points for inventive weirdness. But it suffers from cheesy production values and humdrum performances.

Compared with “Days,” “Touched by an Angel” looks like Bergman’s “The Seventh Seal.”

Tonight’s other highlights

• Billie battles a big shot (Jay Mohr) intent on closing the Candy Store on “Fastlane” (7 p.m., Fox).
• Archeologist Dr. Kent Weeks is host of “Expedition Egypt” (7 p.m., A&E), a new series exploring mysteries of the ancient civilization.
• Scheduled on “48 Hours Investigates” (9 p.m., CBS): A kidnapping victim recounts her ordeal. “Queens Supreme,” which is normally aired in this time slot, has been placed on hiatus.
• A kindly old doctor (Judd Hirsch) falls under suspicion for a baby’s mercy killing on “Law & Order: SVU” (9 p.m., NBC).
• Scheduled on “20/20” (9 p.m., ABC): an interview with Jason Priestley; behind the scenes at “American Idol.”

Series notes

Sterling goes house-hunting on “Mister Sterling” (7 p.m., NBC) … Tom Bergeron is host of a two-hour installment of “America’s Funniest Home Videos” (7 p.m., ABC) … Through the looking glass on “Sabrina, the Teenage Witch” (7:30 p.m., WB).

Marcellus feels the heat on “Hack” (8 p.m., CBS) … A psycho uses kidnapping to re-create his lost family members on “John Doe” (8 p.m., Fox) … Barbara Jean’s makeover leaves her looking like Reba on “Reba” (8 p.m., WB).

Maria tries to rain on David and Sarah’s parade on “Greetings from Tucson” (8:30 p.m., WB).