The world of kids TV is ripe for parody, but Robin Williams' dark comedy Death to Smoochy doesn't have enough of the black humor one wants in such a farce.

However good it is to see Williams in a comedic endeavor after his maudlin missteps Patch Adams and Bicentennial Man, it's too bad he isn't funnier.

Williams plays Rainbow Randolph, the booze-guzzling, bribe-taking sleazebag host of a highly rated children's show. He's at the top of his game, living in a Manhattan penthouse, when a scandal destroys his career. (No echoes of Pee-wee Herman here; the feds got wise to his blackmailing of stage parents.)

The network president (a curiously watered-down Jon Stewart) finds a too-good-to-be-true replacement, the integrity-oozing Sheldon Mopes (Edward Norton ), who dons a fuchsia rhino costume and becomes Smoochy. Mopes quickly makes the transition from playing such gigs as the Coney Island methadone clinic, where his squeaky-clean act barely registers, to a big-time TV show.

Born the same day as Sesame Street's first broadcast, the ultra-earnest Mopes believes in the power of the kiddy pulpit, pushing fruit and soy dogs instead of candy and hot dogs.

Slimy Randolph, now down and out, is out for vengeance. His plan: annihilate the innocent Smoochy. The premise is silly enough to wring out some laughs, but the plot plays out disappointingly.

The usually funny Catherine Keener plays the cynical network exec who falls for Smoochy. Her edgy style works when she's a smirking, cold-hearted businesswoman, but not when she makes a 180-degree turn to being ridiculously softhearted.

Norton is effective enough; his boyishly earnest face suits the role. But some nagging physical details distract from his performance.

It appears that some sequences were reshot well after the main production, because the length of Norton's hair changes dramatically from one scene to the next.

While Williams plays his character like a depraved Willy Wonka, his mugging grows cloying and annoying. His one-liners are funnier than the overall execution of the movie, which is directed by Danny DeVito, who also plays Smoochy's agent, Burke.

The movie is operatic in tone, when a subtler approach might have sufficed.

Smoochy, like the cuddly character, tries to be loved and ends on an unrealistically upbeat note. But it's in better, wittier form just being vicious and biting.