Blood Water

Blood Water is a thrown consumable weapon that deals 20 damage on impact, while also transforming a small number of blocks at the impact site into Crimson, which can then spread to neighboring blocks.

Blood Water affects blocks within a 9-tile radius of the impact point, corrupting up to 57 blocks total. (Untested, assumed from Unholy Water)

It is the Crimson counterpart to Holy Water and Unholy Water, used to respectively create small areas of Hallow and Corruption.