Go ahead: Indulge your inner child. Spend your Presidents Day watching cartoons.

A true fish-out-of-water tale, the new cartoon “My Gym Partner’s A Monkey” (5:30 p.m., Cartoon Network) follows the misadventures of a human boy assigned to a junior high school filled with zoo creatures.

When a typographical error confuses Adam Lyon with an actual lion, he has to share his homeroom, locker and gym class at the Charles Darwin Middle School with chimps, elephants, giraffes and goldfish. Sometimes Adam’s human attributes are a plus, but most of the time he has trouble adjusting to life in a zoo.

Several familiar voices can be heard on “Monkey,” including Tom Kenny (“SpongeBob SquarePants”) as a Jake Spidermonkey. Brian Doyle Murray (“Groundhog Day”) provides the voice of Coach Gills, the football coach who happens to be a goldfish.

“SpongeBob SquarePants” (7 p.m., Nickelodeon) offers a time-travel episode. SpongeBob and his pal Patrick are as excited as they can be to visit a tacky medieval theme restaurant, but after a jousting mishap, they find themselves transported to the real Middle Ages. Or a slapstick version of the Middle Ages populated by creatures very similar to their old Bikini Bottom crowd. Don’t go looking for a history lesson here. At one point, the hapless duo find themselves on the wrong end of a guillotine, a device that wasn’t used regularly for executions until centuries after the Middle Ages. But I’m not one to read too much into a “SpongeBob” cartoon. I’ll leave that to the televangelists.

With so many recent news stories about watching television on your computer or iPod, it’s easy to overlook how much Internet-generated material is ending up on television. “Outrageous & Contagious: Viral Videos” (9 p.m., Bravo) offers an “America’s Funniest Home Video” take on the silly clips and jpegs circulating around the Web. Not to be confused with the VH1 show “Web Junk 20” that airs on Friday nights.

Frankly, I’m surprised there aren’t more shows like this. Or that there isn’t more Web content integrated into scripted comedies and drama. The Internet has been in fairly wide usage for 10 years now.

Tonight’s other highlights

¢ Finola Hughes hosts an all-day holiday “How Do I Look” (5 a.m., Style). Getting up at the crack of dawn to obsess about one’s looks is one way to spend a holiday.

¢ Coverage of the XX Winter Olympic Games (7 p.m., NBC) continues. Scheduled events include figure skating, alpine skiing, freestyle skiing and ski jumping.

¢ A model’s drug problem may be worse than first feared on “House” (7 p.m., Fox).

¢ A two-hour recap of past adventures on “Wife Swap” (7 p.m., ABC).

¢ Frankie Muniz stars as a teen spy in the 2003 comedy “Agent Cody Banks” (7 p.m., WB).

¢ The terrorists put pressure on the president, who, in turn, clamps down CTU on “24” (8 p.m., Fox).

¢ The 2004 “American Experience” (8 p.m., PBS) “Reconstruction: The Second Civil War” concludes.

¢ Fred Astaire and Ginger Rogers hoof their way through the 1934 musical “The Gay Divorcee” (8:30 p.m., TCM). Followed by “Top Hat” (10:30 p.m.), an Astaire-Rogers bauble from 1935.

¢ Divorce can be lethal on “CSI: Miami” (9 p.m., CBS).

¢ The women unload on “The Bachelor: Paris” (9 p.m., ABC).

Cult choice

Featuring ghastly typecasting, the 1980 TV biography “The Jayne Mansfield Story” (8 p.m., Biography Channel) stars Loni Anderson as the doomed blond bombshell and Arnold Schwarzenegger as her muscle-man husband, Mickey Hargitay. A must-see for fans of the dreadful.