This world showcases the Wither Skeleton farm I made in my 14,000+ day Hardcore Minecraft world. I built and tested this entirely in Hardcore Minecraft, and it produces over 7.5 stacks of Wither Skeleton Skulls per hour along with 9 shulker boxes of coal and 12 shulker boxes of bones. Explore the redstone and let me know if you are inspired to build this in your Minecraft world!
The Colonal's Wither Skeleton Farm Team
