Rare Ghast drop from the Nether used to brew Potion of Regeneration and craft End Crystals.
Guide
Build a Nether Portal with obsidian and flint and steel, then enter the Nether dimension.
Search Nether Wastes, Soul Sand Valley, or Basalt Deltas where Ghasts spawn on open solid surfaces.
Use a bow or deflect fireballs back at the Ghast with a melee hit at the right moment.
Pick up the Ghast Tear that drops with a 0-1 rate; Looting III raises the maximum amount.
Use Ghast Tear in a Brewing Stand for Regeneration or combine with Glass and an Eye of Ender for an End Crystal.
Build an open platform high in the Nether to force Ghast spawns and farm tears reliably.
Each Ghast drops 0-1 Ghast Tears, and Looting III raises the maximum to 4 per kill.
Awkward Potion plus Ghast Tear brews a Potion of Regeneration with 45 seconds of duration.
Yes. One Ghast Tear, seven Glass blocks, and one Eye of Ender craft a single End Crystal.
Yes. Open platforms in the Nether force Ghast spawns, making tear farms renewable.