In
NetHack, the Keystone Kops are the minions of evil
shopkeepers. They are summoned and try their best to hunt you down if you
rob a shop by any of the more obvious methods or commit certain other
crimes.
They come in several ranks, including Kop Kaptain (2d6 damage by weapon), Kop Lieutenant (1d8), and Kop Sergeant (1d6). They are not particularly difficult to kill (Lv. 4, 3, and 2, respectively), but can pose big problems for low-level characters. They will throw cream pies to blind you, necessitating the use of the #wipe command.