Jackass front man Johnny Knoxville resurrects OAP character Irving Zisman for his very own movie, Bad Grandpa. We first saw the 90-year-old’s high jinx back on MTV in 2001. He seems to be doing well and aging backwards as he’s now 86 years old in this – must be the fresh cheek of youth rubbing off on him from grandson Billy (Jackson Nicoll) who comes along for the ride. Fear not, this is Jackass with the crude knob turned down a touch but the odd toilet humour gag and latex prosthetics body parts are on show.

Zisman has just lost his wife, had his eight-year-old grandson he barely knows dumped on him by his junkie daughter Kimmy (Georgina Cates) who scarpers at Mum’s (co-writer Spike Jonze in drag) funeral to avoid doing jail-time, and is then forced to make the trip across America to hand his grandson over to his waster father he detests. All widower Zisman wants to do with his newfound freedom is to go to a strip bar, have a good old drink and get laid. Life has other ideas and hiccups along the way as both Grandpa and grandson get themselves in some sticky, messy and totally outrageous situations that include male strippers, beauty pageants and biker bars.

Dickhouse TV’s production reunites Knoxville with his diminutive Fun Size (2012) co-star Nicoll. It’s basically ‘Jackass the Road Trip’ with a sentimental family plot made up of a series of sketches played out using hidden cameras on an unsuspecting public. Admittedly, the first penis joke is within the first ten minutes and it brings tears to the eyes, through laughter then through pain. The rest of the sketches are a mixed bag, either cry-out-loud hilarious (store ride) or drag on (bingo gathering). Some situations seem to mimic the likes of Brüno or Little Miss Sunshine, say, where the gag has been seen/done before. On the whole, it’s the admirable restraint certain members of the public show when an OAP is involved that’s fascinating to watch, plus the near cardiacs others have when things go haywire.

Quite often the scenes with both Knoxville and Nicoll in usually end up with the young star stealing Bad Grandpa’s thunder. Billy is a chubby-faced cutie who needs rescuing from the bad influences in his family. However, he grows to respect his grizzly Pops, probably as he’s just as immature as him. Nicoll commendably plays the straight-laced sidekick most of the time, but other times it’s questionable whether the kid is in on the Jackass joke as his reactions seem too natural to be an act. Knoxville just has a ball in disguise but there are moments beneath the latex mask when even he wonders just how far the joke will go. The end credits show the filmmakers’ reveals to the unsuspecting ‘stars’ in the public.

Bad Grandpa is a blast of light entertainment, however crude things get for some. On a surprise note, it’s the most charming of the Jackass bag of tricks to hit the big screen because of the basic Grandpa-Grandson bonding plot. Knoxville and team have fashioned a unique angle to take the Jackass brand, with Zisman at the helm as the new mascot.