Wren's Halloween plans go awry when she's made to babysit her brother, who disappears into a sea of trick-or-treaters. With her best friend and two nerds at her side, she needs to find her brother before her mom finds out he's missing.
Like the ancient satsumas we used to palm off on unwelcome guisers, this is no treat.
One brief moment, involving a large mechanical chicken humping a car, works, but the rest of the offerings from Fun Size fizzle: teenagers deserve bigger portions of entertainment than these meagre morsels.
Barely developed characters come and go while faux edgy jokes and obscure American pop cultural references fall flat.
As ever, "fun size" translates to "no fun whatsoever".
Johnny Knoxville, of Jackass fame, tries to disguise himself in a blond wig, without success. He must know what we do, that this is stupid and clueless and no fun at all – in any size.
General release. Check local listings for show times.