As “24” (8 p.m., Fox) winds down to its final five hours, veteran actor, director, and my all-time favorite screen sicko Dennis Hopper joins the cast as a shadowy Balkan war criminal whose desire to exact revenge against Jack (Kiefer Sutherland) has set the whole conspiracy in motion.

While many moviegoers only know Hopper from his performances in “Blue Velvet” and “River’s Edge,” Hopper’s career spans several Hollywood generations. As a young man he worked for the big studios, appearing in blockbusters like “Giant,” which starred Rock Hudson, Elizabeth Taylor and James Dean. Hopper all but toppled the old system with his groundbreaking 1969 hit “Easy Rider.” Drugs and personal problems knocked him out of the spotlight until he returned as the strung-out photojournalist in the 1979 Vietnam epic “Apocalypse Now.”

While one hardly thinks of Hopper as a television star, he appeared in two interesting, if forgotten, series that bear some resemblance to the challenging “24.” According to “The Complete Directory to Primetime Network and Cable TV Shows” by Tim Brooks and Earle Marsh (Ballantine, 1999) Hopper acted in the short-lived 1958 CBS drama anthology “Pursuit.” The series presented a new story every week about a hunted man or woman attempting to escape their pursuers. He also acted in the unique NBC series “Espionage” that aired from October 1963 to September 1964. Shot on location in Europe, “Espionage” presented real-life spy stories, ranging from World War I to the ongoing Cold War.

The reality show genre takes an evolutionary step backward with “Going Ape” (7 p.m., Animal Planet). Alastair Fothergill (“Blue Planet”) and conservationist Saba Douglas-Hamilton agree to enter a rain forest in the Ivory Coast, and to live, eat, and sleep with a group of chimps. Forbidden to bring their own food, water, sleeping bags or mosquito netting, they must travel with the chimps, eat what they eat, and find water where they can.

Tonight’s other highlights

Luke prepares for his uncle Louie’s funeral on “Gilmore Girls” (7 p.m., WB).

No matter how many times you’ve seen “The Godfather” (7 p.m., TNN), you can always watch it again.

A messy office prank unravels on “Andy Richter Controls the Universe” (7:30 p.m., Fox).

A kidnapper takes a baby from a maternity ward on “NYPD Blue” (8 p.m., ABC).

Maxine cares for a girl who cannot cope with her demanding father on “Judging Amy” (9 p.m., CBS).

Kathleen takes on a sticky custody case on “Philly” (9 p.m., ABC). “The Court” has been placed on hiatus.