Ecto Mist

, a crafting material obtained from enemies in the post-plantera dungeon

Ecto Mist is a visual effect produced by the Graveyard mini-biome. It is translucent, and has a vague similarity to the clouds on the world generation screen, the difference being it floats along the ground. The mist will appear on top of solid blocks in an unknown radius. Occasional wisps will appear in the air. As more gravestones are placed, the mist gets thicker and the background gets darker.

Ecto Mist can, in conjunction with a crafting station, be utilized to craft certain unique items; most notably blocks and walls that are generated naturally and do not drop as items when destroyed. The player does not need to be in direct contact with the mist for that; being in a Graveyard is sufficient.