Ninja kids unite to protect sacred knife; Eliza talks to animals again; Disney goes ‘Off the Wall’ and ‘Mad’

Yakko and Wakko and their sister Dot can be seen wreaking havoc on every person they meet during an eight-hour marathon of Steven Spielberg Presents Animaniacs (Cartoon Network, Sunday at noon). The fun-loving siblings also can be viewed daily at 8:30 p.m. For ages 5 and up.

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In “3 Ninjas Kick Back,” on “The Wonderful World of Disney” (ABC, Sunday at 7 p.m.), three suburban kids, trained in martial arts by their grandfather, face three heavy-metal rockers to protect an ancient ceremonial knife in Japan. They get help from a skillful Japanese girl. For ages 11 and up.

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As a teen, “Young Hercules” (Fox Family Channel, Sunday at 8 p.m.) gets into more mischief than heroism. But he finds his calling, which is to help the helpless. For ages 8 and up.

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Eliza Thornberry is an adventurous 12-year-old girl with a very big secret: She can talk to animals. In the premiere episode of the animated series The Wild Thornberrys (Nickelodeon, Tuesday at 8 p.m.), she and her family are forced to spend the night in the African savanna after their convoy is swept away in a flood. Naturally, Eliza takes the opportunity to go hunting with lions. For ages 6 to 11.

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Teenagers who can transform themselves into animals and slug-like aliens are on a mission to save the world from an evil group known as Yeerks. In the premiere of Animorphs (Nickelodeon, Friday at 8:30 p.m.), viewers are introduced to the five teenage heroes who must fight the evil invaders and still get their homework done. For ages 6 and up.

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Young viewers get four hour-marathon of game shows in Off the Wall and Mad Libs (Disney Channel, Saturday from 7 to 11 p.m.). “Off the Wall” features pre-taped video challengers competing against in-studio contestants in such stunts as unrolling rolls of toilet paper and naming as many U.S. presidents as possible. “Mad Libs” pits two teams of kids in a head-to-head contest of wits for the most creative and funniest phrases and stories. For ages 8 and up.