Ichor

Ichor is a crafting material dropped by Ichor Stickers in the Hardmode Underground Crimson. It is the Crimson counterpart to the Corruption's Cursed Flame.

Tips
Ichor does not burn up in lava, so pouring lava on Ichor Stickers is a possible way to collect Ichor. This also means areas with lava can be used as natural traps to farm Ichor.

Trivia

 * Ichor, in Greek mythology, is the golden ethereal fluid that flows in the blood of gods and immortals, as also said in the item's tooltip. It also means a discharge from a wound or ulcer. H.P. Lovecraft, the creator of the original Cthulhu character, often used "ichor" in his descriptions of otherworldly creatures.
 * It can be pronounced "eye-core", or "eye-ker". It can be pronounced "Iker" to rhyme with "sticker". Hence the name of the enemy, Ichor Sticker.