Quick Scoop To get the Guide Voodoo Doll for the Underworld in Terraria , defeat Voodoo Demons in the Underworld, then use the doll by throwing it into lava there to summon the Wall of Flesh. The Guide NPC must still be alive, and it has to be Underworld lava specifically, not lava elsewhere.

How it works

  • Find the Underworld at the bottom of the map.
  • Look for Voodoo Demons there and defeat them to get the Guide Voodoo Doll.
  • Make sure the Guide is alive before you use the doll.
  • Throw the doll into lava in the Underworld to trigger the boss fight.

Important detail

If the Guide is already dead, the summon will not work. Also, lava in other places will not count; it has to be lava in the Underworld.

TL;DR

Kill Voodoo Demons in the Underworld, get the Guide Voodoo Doll, and drop it into Underworld lava with the Guide alive.