Smashing, Poppet!
Common51.3%ObjectiveOptionalAnywhere
Using explosives or your trusty hammer, smash a Shadow Orb or Crimson Heart in the evil parts of your world.
Shadow Orbs (Corruption) and Crimson Hearts (Crimson) sit at the bottom of the evil biome's chasms, behind ebonstone/crimstone you'll need bombs or a nightmare-tier pickaxe to reach. Smash one with a hammer or explosives for loot (Musket or Undertaker among it); every third smashed summons the biome's boss, and smashing also rolls the meteor event. One smash pops this.