Ellen DeGeneres hosts the 29th annual “Christmas in Washington” (7 p.m., TNT) celebration benefiting the Children’s National Medical Center. Look for the president, first lady and other dignitaries as well as performances by Mariah Carey, Miranda Cosgrove, Annie Lennox, Maxwell and Matthew Morrison.

• Christiane Amanpour puts the accent on world health issues on “20/20” (9 p.m., ABC). She reports on malnutrition in Guatemala and informs viewers how they can make a difference for the world’s sick and hungry.

• Jason Alexander (“Seinfeld”) and Sabrina Bryan (“The Cheetah Girls”) guest star on the cartoon comedy “Fish Hooks” (7:30 p.m., Disney). This episode sends up celebrity and the acting game, and sends Bea, Milo and Oscar to the entertainment capital, a place called Hamsterwood, where they appear on a show on Hamster TV, produced by a Mr. Nibbles (Alexander) and starring Pamela Hamster (Bryan). This could be Alexander’s greatest moment since “Dunston Checks In.”

• “Top Chef” veteran Richard Blais combines a flair for the laboratory with culinary expertise in the series “Blais Out” (9 p.m., Science). Forget mere spatulas: The man loves his liquid nitrogen! He uses that and other unlikely technology to re-engineer dishes both new and familiar.

• As readers of this column know, the wags at TCM reserve the wee hours of late Friday and early Saturday for underground movies and weird classics. Tonight, they’ve unearthed a film that may shock you and make you wonder. Can the director of an influential slasher film also make a heart-warming holiday classic?

Set in a sorority house (you know where this is going), the 1974 shocker “Black Christmas” (1 a.m., TCM) was also released as “Silent Night, Evil Night.” It featured a very dark plot and a rather remarkable cast, including Keir Dullea (“2001”), Olivia Hussey (“Romeo and Juliet”) and a pre-“Superman” Margot Kidder. But the most remarkable screen credit belonged to the director Bob Clark, who, nine years later, would make “A Christmas Story,” one of the most beloved and often-repeated holiday favorites ever.

Tonight’s other highlights

• The voices of Neil Patrick Harris, Jennifer Love Hewitt and Alfred Molina animate the 2009 Christmas fable “Yes, Virginia” (7 p.m., CBS).

• Jimmy Durante narrates the 1969 special “Frosty the Snowman” (7:30 p.m., CBS). John Goodman does the same for “Frosty Returns” (8 p.m., CBS) from 1992.

• A trash compactor recycles the human spirit in the 2008 animated fantasy “WALL-E” (7:30 p.m., Family).

• Maureen O’Hara, John Payne, Edmund Gwenn and a young Natalie Wood star in the 1947 holiday favorite “Miracle on 34th Street” (7 p.m. and 8:15 p.m., AMC).

• A homemade bomb threatens the city on “Blue Bloods” (9 p.m., CBS).

• An expert helps a home declutter on “Stuffocating” (9 p.m., TLC).