“Nature: The Beauty of Ugly” (3 a.m., PBS): Finally, a special that glorifies ugly

“Nature: The Beauty of Ugly” (3 a.m., PBS): Finally, a special that glorifies ugly creatures.

“A Charlie Brown Thanksgiving” (8 p.m., ABC): Who put Snoopy in charge? On “A Charlie Brown Thanksgiving,” the beguiling beagle whips up a holiday feast featuring popcorn and toast. That prompts a major snit by Peppermint Patty, who almost ruins the day.

“Frontline: On Our Watch” (9 p.m., PBS): Khartoum’s newfound oil wealth set the stage for conflict with the long-neglected region of Darfur in western Sudan, where rebel groups emerged to claim a share of the country’s burgeoning wealth. In response, the Sudanese government armed a proxy militia and unleashed the so-called “Devils on Horseback” on the rebels and civilian farmers in a stampede of brutality. Over the past four years, at least 200,000 people have been killed, 2.5 million driven from their homes, and mass rapes used as a weapon of war. Now PBS’ “Frontline” asks why the international community and the United Nations has failed to stop the slaughter, in the documentary “On Our Watch.”

“Frank TV” (11 p.m., TBS): Comedian and master impressionist Frank Caliendo puts a new face on late-night television with “Frank TV.” It’s a sketch-comedy show that has the gregarious goofball holding court from his living-room set. Impressions featured in the opener include: Robin Williams, Jerry Seinfeld, John Madden, Bill Clinton, George W. Bush, Dick Cheney and Charles Barkley.