Volcano

The Volcano is an overworld structure that houses multiple mobs and a new type of ore. They don't spawn in any icy or cold biomes, nor the Breakfast Bog (for the breakfast equivalent to the Volcano, see Wafflecano).

Mobs: You can find Flare Iron ore in this structure, on the inside walls.
 * Magmatic Slime
 * Magma Beetle
 * Ash Elemental