The tween comedy “iCarly” (7 p.m., Nickelodeon) says goodbye after five seasons. The show stood out by trying to integrate Web content and old-fashioned sitcoms. Or, at least it was a sitcom about a kid (Miranda Cosgrove) with her own website.

The show followed the trend of youth-centric cable sitcoms to blend live action shenanigans with cartoon logic. Like many comedies going back decades, it featured family life with absent parents and a sense of community cobbled together by friends and siblings. And, as if to compensate for those absent parents, Carly and her friends lived in a fantasy world of consumerism, where money was rarely an object.

Tonight marks the return of Carly’s long-missing father, an Air Force officer who has been living abroad for the duration of the show. Apparently, the Web-savvy Carly never thought to Skype with her dad.

• Shows like “iCarly” generally depart when their stars get a tad too old to be believable as tweens. Or when said talent starts looking for more grown-up projects. That never happens to cartoon characters. If Bart Simpson aged like the rest of us, he’d be in his 30s now. And let’s not even think how Charlie Brown (bald at 4!) might look, now that he’s pushing 70.

And time moves even more slowly at the bottom of the sea. SpongeBob SquarePants, our favorite porous, rectangular hero since 1999, gets his own stop-motion, animated holiday special in “It’s a SpongeBob Christmas!” (8:30 p.m., CBS). Loosely based on the song “Don’t Be a Jerk (It’s Christmas)” by Tom Kenny (the voice of SpongeBob) and Andy Paley, the special revolves around the secret formula for Krusty Krab’s secret Krabby Patty formula.

• Other holiday specials include “Frosty the Snowman” (7 p.m., CBS) and “Frosty Returns” (7:30 p.m., CBS); “Happiness is a Warm Blanket, Charlie Brown” (7 p.m., Fox) and “Grandma Got Run Over by a Reindeer” (7 p.m., CW); “Hoops & Yoyo Ruin Christmas” (8 p.m., CBS) and “The Happy Elf” (8 p.m., CW).

Tonight’s other highlights

• On back-to-back episodes of “The Simpsons” (Fox): a flash-forward to future holidays (8 p.m.), exiled Simpsons live off the grid (8:30 p.m.).

• Charlie Rose interviews Drew Brees, Alicia Keys and Sean Penn on “Person to Person” (9 p.m., CBS).

• “Unlikely Animal Friends” (7 p.m., 8 p.m. and 9 p.m., Nat Geo Wild), offers tales of interspecies affection.