TV REVIEWS : Fox Changing the Face of Saturday Morning Kidvid : Television: Thanks to creative cartooning, adults as well as children are being attracted to the tube.

Having revived prime-time animation with “The Simpsons,” Fox seems well on the way to sparking a similar renaissance on Saturday morning. Three of the network’s first children’s cartoon shows are imaginative, original and entertaining: For the first time in years--if not decades--watching Saturday morning television is fun for adults as well as children.

Fox has allowed a creative group of writers, artists and directors to exercise their talents freely, and the results sparkle with imagination, a quality their network counterparts sorely lack.

Created by children’s author-illustrator Shane DeRolf, the delightful “Zazoo U” focuses on the often surreal goings-on at a bizarre school. Two rap-speaking birds walk on and change the backgrounds whenever the scene shifts. The casual insanity of “Zazoo U” is utterly unlike anything that’s ever been on Saturday morning.

In keeping with the trend toward younger characters on children’s shows, “Tom & Jerry Kids” stars junior versions of the cat-and-mouse team that won Bill Hanna and Joe Barbera seven Oscars. Like the original shorts, the new cartoons use no dialogue, only sight gags--a welcome respite from the talky formulas of so much kidvid.

“Droopy and Dribble” brings back Tex Avery’s phlegmatic basset hound, with a slightly smaller son. The wild takes and exaggerrated expressions may not be as perfectly timed and animated as they were in Avery’s theatrical shorts, but this frenetic show is truer to the spirit of those classic ‘40s cartoon than the flamboyantly stale “Tiny Toon Adventures.”

Comedian Howie Mandel provides the voice for a suburban father and his 4-year-old son in “Bobby’s World.” Much of the action takes place in the world of Bobby’s overly fertile imagination: When Dad announces the family’s going to visit Aunt Ruth, Bobby pictures himself commiserating with distorted victims who’ve had their cheeks pinched out of shape by the terrible Aunt Ruth Monster. Both funny and charming, “Bobby’s World” deserves a prime-time spot.

In contrast, the new shows on ABC, CBS and NBC suggest that a truckload of threadbare teen-age sitcoms crashed on the way to the dump, flooding the screen with stale ideas. Viewers can tell these weary retreads are supposed to be hip: The characters use dude at least once in every sentence.

“New Kids on the Block” (ABC), combines a badly animated version of the popular bubble-gum rock band with cuts from concert footage. Apparently the biggest problem the Kids face is how to escape the hordes of female admirers, and this fanzine mentality makes the show even less interesting than the group’s music.

Down the block, as it were, are “The Guys Next Door” (NBC), a live-action attempt to re-do “The Monkees” in the ‘90s. The producers apparently spent more on hair mousse than writers, and the show demonstrates its ecological awareness by recycling used gags. If these guys live nearby, the neighborhood must be hell.

The live action/animation “Kid ‘n’ Play” (NBC) features lame stories about a teen-age rap group and stiff animation. Black characters are rare on Saturday morning TV, and it’s regrettable this show doesn’t have more going for it.

“Rick Moranis in Gravedale High” (NBC) features an uninteresting caricature of the movie star riding herd on a standard assortment of teen-age monsters. “Bill & Ted’s Excellent Adventure” (CBS) repeats the inanities of the recent film about two dimwitted but cool dudes traveling through time.

Rounding out the pseudocomic slate is “Little Rosie” (ABC), featuring a cartoon version of Roseanne Barr as a child. Unlike her brash adult alter-ego, the young Roseanne is just an ordinary kidvid character. The stories that send her on imaginary adventures use material similar to “Bobby’s World,” but the difference is the one letter that distinguishes class from crass.

“The Wizard of Oz” (ABC) must rank as the nastiest trick that’s been played on the inhabitants of L. Frank Baum’s enchanted land since the villainous Mombie cast a spell on Princess Ozma. The producers foolishly based the program on the classic 1939 film: Everybody knows how Ray Bolger, Bert Lahr, Jack Haley, Margaret Hamilton et al. are supposed to look and move and sound, and the cartoon versions don’t even come close. Watching this show is a bit like watching a cassette of the MGM musical that got caught in the trashmasher. “Oz” fans should consider dropping a house on ABC headquarters.