If Jamie Kennedy's ultimate goal is to dispel the lingering popular notion that he's a talented comedian, he could hardly have picked a better vehicle than “Son of the Mask.” After all, by starring in the film — a follow-up to the 1994 hit “The Mask” — he's effectively inviting comparisons to Jim Carrey, and how laughable is that? No less absurd than, say, Ashlee Simpson finishing up a set for Janis Joplin.

Not that Carrey would have fared much better in this punchless, infantile attempt to rebrand “The Mask” as wholesome kibble for the whole family. Lame material is lame material, no matter who's wearing the dentures and green face latex.

Kennedy (“Malibu's Most Wanted”) is awkward and gratingly dim as Tim Avery, a struggling cartoon animator who stumbles upon the enchanted id-releasing mask featured in the first movie, wows his co-workers with his newfound cartoonish charisma and promptly impregnates his wife (Traylor Howard from “Me, Myself and Irene”) with his demon Mask-seed (perhaps the R-rated version will be on the DVD). Nine months later, a baby son is born — outwardly normal, but prone to bouts of digitally rendered Looney Toon miscreance.

From that point on, it's misadventures in babysitting, as Tim sweats to meet a deadline while the kid apes his favorite cartoon characters, including Michigan J. Frog, the dancing, “Ragtime Gal”-singing amphibian recently pressed into service as the WB mascot. Anyone who got the creeps from Ally McBeal's dancing baby will probably experience a similar reaction to “Son of the Mask,” but these — sadly — are the liveliest, most satisfyingly madcap scenes in the movie. Director Lawrence Guterman (“Cats & Dogs”) comes close to synthesizing the charm of the Roadrunner/Wile E. Coyote cartoons when the baby engages Tim's attention-starved Jack Russell terrier in a round of bloodlessly violent horseplay.

The lows in “Son of the Mask” are low indeed — flat jokes, mealy camera work and a bizarre, ineffective villain in Loki, the Norse god of mischief (Alan Cumming) who mischievously visits the Avery household looking for his mask. Cumming has done some interesting film work (“The Anniversary Party,” “X-Men 2”), but if his career ended tomorrow, the only thing he'd be remembered for is playing impish, vaguely gay villains in children's movies. Thanks, but the world already has a Rip Taylor.

Kennedy is hard to figure out. Reasonably funny playing a privileged teen rapper in “Malibu's Most Wanted,” serviceable as a moronic GI in “Three Kings,” the redhead has only truly thrived making clowns out of oblivious noncelebrities on his defunct WB TV show, “The Jamie Kennedy Experiment.” What irony. In this second-generation snoozer, the only person he's clowning is himself.