Cistern Job
The act of removing the lid off the back of the toilet and planting a stool in the cistern to spite an ememy. The easiest way is for the perpetrator to perch with their feet on the toilet seat and poo directly into the cistern. Often seen as one step further than a 'reverse kanga' or 'crocodile skiddy' as everytime the victim attempts to flush the toilet to rid it of its contents it refills from the cistern with a cruel mix of poo and water. Particularly effective as it is often not noticable straight away as there is no actual poo in the bowl but fills up over time making it hard to find out who did it.
My mother-in-law is such a bitch. I am going to teach her a lesson and perform a revenge cistern job in her toilet.