Bad Grandpa starts with the death of Irving Zisman’s wife. Irving is an 86-year-old widower who reacts to his wife’s passing with unexpected relief and even joy, rather than the expected sorrow. Meanwhile, his 8-year-old grandson Billy is left in his care because Billy’s mother, Kimmie, has been sent to prison for violating her parole. Irving reluctantly agrees to take Billy from Nebraska all the way to Raleigh, North Carolina so he can live with his father.
Right from the beginning, the journey is far from ordinary. Irving exhibits extremely inappropriate behavior: he laughs at the funeral, flirts in ridiculous ways, and even embarrasses himself and Billy in public. The film mixes a loose narrative with hidden-camera pranks: Irving and Billy wander into real-life situations with unsuspecting people, generating shocking, often crude humor. The comedy comes largely from the reactions of strangers who have no idea they’re being filmed.
As the road trip continues, there are a number of standout episodes. Irving tries to ship Billy through the post office, fails spectacularly, and then drags his wife’s corpse around in the trunk of his car. They crash a beauty pageant, visit biker bars, stop at motels, and cause chaos in diners and supermarkets. The mix of scripted plot points and improvised pranks becomes a hallmark. Each stop becomes an excuse for Irving to cause more trouble, often at Billy’s expense but surprisingly with some moments of bonding.
Billy, though young, gets dragged into Irving’s lunacy. He often becomes embarrassed, confused, or morally torn by what his grandpa does. While some of Irving’s antics are gross or tasteless, Billy’s presence adds a humanizing element. There are moments when their relationship seems more than just for laughs — when Billy shows concern, or when Irving behaves in a way that reveals affection or responsibility.
The climax involves Irving finally disposing of his late wife’s body by throwing it into a river, fulfilling his bizarre road-trip promise of delivering closure, at least in the most literal sense. Along the way, the film presents outrageous physical comedy—Irving getting his penis stuck in a vending machine, flatulence contests in diners, comedic chaos in public places—all mixed with reactions from people who believe it’s just another strange old man or prank.
