Minecraft wiki entry for Obsidian_farming, associated text: A lesser used method of farming obsidian is by caging withers in the lower part of the eastern End spike, causing the withers to blow up the pillar when regenerated, wielding up to 600,000 obsidian per hour when using the pillar completely. Only the lower part of the pillar can be used as the higher part generates air blocks around itself when regenerating, this would cause the withers to escape. After the withers are trapped inside the pillar, the ender dragon summoning ritual is started, causing the pillars to regenerate. The ritual is either aborted before the ender dragon respawns or the ender dragon is killed by a specialized contraption such as a railgun. Such a desing is shown by cubicmetre.