From the medieval days when a person took a needle and tried to find a witch's mark ( a area of skin that wouldn't bleed) and prove a person was a witch. The pricker was paid for their work and would prick a person hundreds of times to find a witch's mark. modern context would be a person who tries to find anything wrong with someone so they can deliver them to somebody and receive a profit.
Mark is the office nark, a real pricker. Anything you say to him goes to the boss and is made to sound as bad as possible. He has out lasted everyone here. Mark also asks the people the boss doesn't like a lot of personal questions.
by Tim Fyock August 25, 2005