A kuker (plural: kukeri) is a merchant found in the dNetHack Lost Cities. Each level there above Gulf of N'Kai can have up to 2 kukeri, with a 7% chance each. Each kukeri has an insight limit as well, ranging from 1-40.
Kuker are always generated with a +7 wooden weapon with the holy and red-hot object properties. It has a 50% chance to be a scimitar, a 25% chance to be a quarterstaff, and a 25% chance to be a spear. They also are always generated with a normal bell.
The primary purpose of a kukeri is to offer services you can't find anywhere else. These services are reusable, with the exception of sanctification, which removes the kuker along with all non-unique items it is carrying. Some of these services will not be available unless you meet their criteria.
They are most useful in sanctifying weapons. This can be used to add a large amount of extra damage to any weapon, so you can upgrade your current endgame weapon to be even better, or make a less viable weapon more effective. The complete dungeon, minus Fort Ludios, can barely end up with enough gold to sanctify two weapons, but it's unlikely that you'll even find two kukeri to sanctify with.
|Drive out curses||7 gold||Uncurses all cursed items in your open inventory, and unpunishes you.|
|Blessing of good fortune||70||Fully maximizes your innate luck.|
|Bless wielded item||700||Blesses your currently wielded weapon. If the weapon's enchantment is under 3, it will be set to 3. You must be wielding a weapon.|
|Lift sterility curse||7000||Makes you fertile again. You must be sterile.|
|Sanctify your weapon||70000||Blesses your current weapon. If the weapon's enchantment is under 3, it will be set to 3. Adds the holy property, removing the consecrated property in the process. You must be wielding a weapon.|