Duck, Duck, Goosed is a unique side quest in The Witcher 3: Blood and Wine that's very easy to miss, especially since it has a limited window of completion and a reward that you might not understand. If you're looking for the Duck, Duck, Goosed quest and you want to know what the Golden Egg reward does, then you can find the answers you seek right here!
This side quest is only available during "Beyond Hill and Dale", so if you leave the Land of a Thousand Fables, or complete " Blood Simples " instead, then you won't be able to do this side quest.
How to Start & Complete Duck, Duck, Goosed in The Witcher 3
While you're in the Land of a Thousand Fables during the "Beyond Hill and Dale" main quest, you can find a noticeboard in the south area by the snowy town with the girl who sells flint. At the noticeboard, pick up Contract: Loosey this Goosey!, which will start the Duck, Duck, Goosed! side quest.
You will now need to find the goose's home, which is in the west area. Outside the front door, you will need to track the goose feathers with your Witcher Senses. The track continues east, where you will find two bandits and Redbeard, all of whom are weak to silver swords, not steel swords!
Once they are dead, loot Redbeard to get the Cage Key, which can be used on the goose's cell to free her. Once freed, the contract will be completed, and you will be awarded the unique Golden Egg.
How to Use the Golden Egg in The Witcher 3
The Golden Egg can be found in your Food and Drink inventory menu, and you can then eat it like you would any other food item. Eating the Golden Egg will award you with a skill point, and not much else. Since you should already be over level 50 in Blood and Wine, this isn't going to be very rewarding or useful.
The Golden Egg is not a trophy for Corvo Bianco, nor is it something you can sell. If you complete "Beyond Hill and Dale" then the Golden Egg is forever lost, so make sure you use it while you remain in the Land of a Thousand Fables, or you would have completed the contract for nothing!
Source: Game Rant