Stardew Valley has its fair share of chickens with five different types in total as of the 1.5 update. One of the more unique types of chicken in the game is the void chicken which also lays void eggs that can be turned into void mayonnaise. Here is how to go about getting a void chicken.
Getting and Upgrading a Coop
As with any of the other varieties of chicken in Stardew Valley, players will first need to have a coop built to house them. Robin is the local carpenter and will build a coop over the span of three in-game days if she is given 4,000 gold, 300 wood, and 100 stone. Simply tell Robin the desired location of the coop on the farm and she will get to work the following day. Players will also need an incubator to get a void chicken and as such will need to upgrade their coop to a big coop. Return again to Robin with 10,000 gold, 400 wood, and 150 stone and she will upgrade the coop. Once it is complete, players will have access to the incubator where a void egg can be placed once it is obtained.
Obtaining a Void Egg from the Witch
Once a coop has been built on the farm and players can buy chickens, players technically are also able to get void eggs. When going to bed at night, there is a chance for a witch to fly over a coop and leave a void egg. However, the witch appearing is a very rare event with only a 1% chance of happening. Even if the witch does visit the farm, there isn't a 100% chance that she will leave a void egg in a coop.
Obtaining a Void Egg from Krobus
Going to Krobus is a much more reliable way to get a void egg. There is still an obstacle to getting a void egg from Krobus however and that is the fact that Krobus lives in the sewers. When players first start the game they will not have access to the sewers.
The only way to gain access to the sewers is to donate 60 different items to the museum. These items can be gems or artifacts, but they have to collectively equal 60. Players will want to head to the mines to find gems and will want to dig up spots in town with worms as those can produce artifacts. Once that goal is met, Gunther will appear at the farm the next day to give players the Rusty Key which will allow access to the sewers.
There is a sewer entrance in the forest and in town. Once inside, players will meet Krobus who will sell the player various items including void eggs for 5,000 gold. Once the void egg has been obtained, simply place it in the incubator in the coop and wait. It will take 6 days to hatch unless players have the coopmaster profession obtained at farming level 10 after choosing the rancher profession at farming level 5. This perk will cause void chickens to hatch in 3 days.
Just for the sake of being thorough, it should be noted that void eggs can also be obtained from Void Salmon in a fish pond, but Void Salmon cannot be obtained without first having access to Krobus.
Uses for Void Chickens
Void chickens are not significantly more useful than other chickens, but they are a more useful variant than blue chickens as they continually produce void eggs. Void eggs can also be used in the mayonnaise maker to make void mayonnaise. Void products serve as terrible gifts however as everyone but Sebastian and Krobus hate void eggs and even Sebastian hates void mayonnaise. Krobus loves both products though and Sebastian loves the void eggs in their base form. Void eggs can be substituted for regular eggs when cooking however.
Stardew Valley is available now on Mobile, PC, PS4, Switch, and Xbox One.
Source: Stardew Valley Wiki