Roald Dahl 
Roald Dahl’s The Twits (NHB Modern Plays) [EPUB ebook] 

Mr and Mrs Twit are not very nice. In fact they're extremely nasty. They're nasty to each other, and they're VILE to everyone else.
They hold a family of monkeys hostage in a cage and force them to stand on their heads. ALL THE TIME.
We told you they weren't very nice. Can the monkeys find a way to show those vicious Twits what for?
Mischievously adapted from Roald Dahl's story, acclaimed playwright Enda Walsh turns The Twits upside down and brings this revolting revolution to the stage.
First performed at the Royal Court Theatre in April 2015.