Duck is an animal in Stardew Valley which produces Duck Egg every other day once mature, and Duck Feather after reaching a good relationship with the farmer. The Duck, which will be unlocked when getting a Big Coop lives in the the coop. Ducks can be purchased at Marnie Ranch for 1,200g or be hatched by placing a Duck Egg into an Incubator, taking 9,000m (5d 16h 40m) to incubate, or 4,500m (2d 21h 40m) with the Coopmaster Profession. A duck is able to swim in bodies of water on the farm.
After update 1.5, ducks were given the ability to swim on bodies of water around a player's farm, though is an uncommon occurrence.