I had an experience once where a toxic, delusional, pathological liar of an employee was hired and started making up wild accusations about their coworkers on day 1. They then proceeded to do no work and had their role at the company progressively minimized so that they could have satisfactory performance for how little they were doing (and couldn't do much damage). There was no way the company was going to fire them and thankfully after a couple of years they decided to quit, despite making their entire team miserable that whole time.