Monday's Highlights: 'Castle' on ABC
The Sing-Off: Groups from all three seasons perform holiday and inspirational songs in this special episode (8 p.m. NBC).
Gossip Girl: Lily (Kelly Rutherford) throws a party to give Charlie (Kaylee DeFer) an official introduction to New York society in this new episode (8 p.m. KTLA).
Saved: Most of the stories told in this series feature heroic animals who literally save people’s lives, but the story of animal science professor and autism advocate Temple Grandin is featured in tonight’s episode (8 p.m. Animal Planet).
The Best Thing I Ever Ate: Bobby Flay, Alex Guarnaschelli, Curtis Stone and Michael Symon unwrap their most beloved holiday treats (8 p.m. Food).
Two and a Half Men: Bridget (Judy Greer) reappears in Walden’s (Astin Kutcher) life in this new episode (9 p.m. CBS).
Hart of Dixie: Zoe (Rachel Bilson) coaches Rose (McKaley Miller) for a local beauty pageant that Lemon’s (Jaime King) sister (Claudia Lee) is the favorite to win in this new episode (9 p.m. KTLA).
Neverland: This new version of the Peter Pan tale concludes (9 p.m. Syfy).
Enlightened: This new episode is all about Amy’s (Laura Dern) mom, Helen (Diane Ladd) (9:30 p.m. HBO).
A Charlie Brown Christmas: Charlie Brown and Linus search for the true meaning of Christmas in this holiday classic (8 p.m. ABC). “Prep & Landing: Naughty vs. Nice” follows at 8:30 p.m.
American Country Awards: Trace Adkins and Kristin Chenoweth host the ceremony and will be among the performers, along with Blake Shelton, Pistol Annies, Thompson Square, the Eli Young Band and the Band Perry. Jason Aldean and the Zac Brown Band lead the nominations with eight each (8 p.m. Fox).
25 Most Heartwarming Holiday TV Moments: This new special recalls TV scenes from holiday episodes of classic series that tug at the heartstrings (8 p.m. TV Guide).
Football: The San Diego Chargers visit the Jacksonville Jaguars (5:30 p.m. ESPN).
Photo: Eric McCandless / ABC