Blood Sack is a pickup in Fiend Folio, a mod for The Binding of Isaac.

Spawns 1-3 heart pickups from the following:
• 37.04% → Half Heart
• 29.63% → Heart
• 14.81% → Double Heart
• 11.11% → Scared Heart
• 3.7% → Blended Heart
• 3.7% → Bone Heart

• Check out the pickup description on the mod's external Wiki.
• Download Fiend Folio from the Steam Workshop.