LOS ANGELES - If the "Jackass" movies have always spit exuberantly in the face of age and mortality, it's fitting that co-creators Johnny Knoxville, Spike Jonze and Jeff Tremaine have now given us one devoted to Knoxville's octogenarian alter ego, Irving Zisman. Strangely touching, too, given that the "Jackass" boys are all in their 40s now and still throwing caution to the wind.
Strapping a loose narrative framework onto the series' patented stunts and candid-camera gags, "Jackass Presents: Bad Grandpa" shows there's still comic life in this decade-old franchise - provided, of course, the sight of a senior citizen getting his penis caught in a vending machine is the kind of thing that brings a smile to your face.
Originally introduced during the final season of "Jackass" on MTV, the Zisman character has been a mainstay ever since, sometimes paired with Jonze's nonagenarian prostitute character Gloria for maximum elder-care chaos. In "Bad Grandpa," Irving's family is fleshed out to include a crack-addict daughter (Georgina Kates), who, on the verge of returning to prison, tasks Irving with transporting his 8-year-old grandson (Jackson Nicoll) to the boy's deadbeat father (Greg Harris) in North Carolina.
That's the "plot" as far as it goes, which is really just a device for putting Knoxville and the cherubic, foul-mouthed Nicoll ("The Fighter") in a car together and letting them wreak their inspired havoc across state lines. A couple of the movie's best and most outrageous payoffs come right up front, when Irving enlists a couple of unwitting furniture movers to help him load the corpse of the late Mrs. Zisman (Catherine Keener) into his car, then tries to circumvent the road trip by simply UPS-ing little Billy all the way to Raleigh.
The m.o. of "Jackass" has always been the comedy of physical pain - a "Three Stooges" for the X-Games era - married to a kind of anarchic street theater. Knoxville and company delight at finding ways to make life veer off its neatly ordered path and in capturing the flummoxed reactions of those who bear witness. Here, they take an added glee in playing off social mores concerning children and the elderly - how they should be treated, and when they shouldn't be held responsible for their actions (as when Irving and Billy eat their way through a mini-mart, then make a run for it).
Even with Knoxville buried under layers of latex, his willingness to do anything for a laugh is a gift that keeps on giving, whether he's getting smashed between the jaws of a spring-loaded adjustable bed or hurled through a plate-glass window by a malfunctioning strip-mall kiddie ride. But the most talked-about sequence from "Bad Grandpa" seems likely to be Irving's impromptu bootie shaking (complete with low-hanging elastic scrotum) on the floor of an all-black male strip club.
"Bad Grandpa" isn't as sustained a piece of work as the earlier "Jackass" pics, and it can even seem tame in light of the more outrageous bits in "Borat" and "Bruno" - perhaps a sign that Knoxville et al. are ever so slightly maturing. Too much of the film gets bogged down in Irving making lewd passes at uninterested younger women (and one possibly interested drive-thru attendant), but even at its low ebb, the movie effuses an infectious, mischief-making joy.
After spending most of the movie as the relative straight man, Nicoll proves himself every bit as fearless as his battle-scarred mentor during a drag-kiddie-pageant finale that's like tobacco juice in the eye of "Little Miss Sunshine."
"Jackass Presents: Bad Grandpa," a Paramount release presented with MTV Films, is rated R by the Motion Picture Association of America for "strong crude and sexual content throughout, language, some graphic nudity and brief drug use." Running time: 91 minutes.
MPAA rating definition for R: Restricted. Under 17 requires accompanying parent or adult guardian.