Living Fire Blocks

Living Fire Blocks are animated background furniture blocks that, when placed, resemble small animated flames and emit faint orange light. They deal no damage on contact and can be freed with any pickaxe or drill. Living Fire Blocks have a chance of being dropped by any enemy killed in the Underworld during Hardmode, and drop in stacks of 20–50 at a time.

While Living Fire Blocks can be placed in a manner similar to traditional, foreground blocks, they are actually in the background, similar to furniture, allowing the player to walk directly through them. They can attach to each other horizontally as well as vertically, but other traditional, foreground block types will not attach to them.

There are five color variations of the base Living Fire Block, all of which are crafted from it. They are functionally identical.

Types
{| class="terraria sortable lined" ! colspan=2 | Item ! Placed ! Tile ID

Tips

 * Living Fire Blocks could be considered more useful than torches because, besides being easy to farm, they can be placed anywhere and are not displaced by liquids.
 * Summoning King Slime in the Underworld can be an excellent way to farm for the fire blocks. Each of its summoned slimes killed gives the same chance of dropping Living Fire Blocks as any enemy, offering an average of two drops per kill (approximately 40–100 blocks per King Slime summoned).

Trivia

 * The and the  item sprites are identical.
 * Living Ichor Block does not contain the word "Fire", unlike all the others.
 * The Living Demon Fire Block is tied with Shroomite Plating for having the longest crafting tree of a block.
 * It would appear that the Wall of Flesh is able to drop Living Fire Blocks, likely with the same chance as a normal enemy.

History
Blocs de feu vivant 살아있는 불꽃 블록 活火块