Bloody Spine

The Bloody Spine is a consumable item used to immediately summon the Brain of Cthulhu while in the Crimson. It can be crafted at a Crimson Altar or a Demon Altar from 15 Vertebrae dropped by Blood Crawlers, Face Monsters, and Crimeras. Attempting to use it outside the Crimson will have no effect and will not consume the item.

Trivia

 * While it is the counterpart of Worm Food, the Bloody Spine is actually easier to make, since it does not require anything besides Vertebrae