- 3x Yellow Backbones are dropped by The One Reborn.
- Nightmare of Mensis:
- Yellow Backbone x2, chest on left side of the Library in Mergo's Loft: Entrance
- Can be dropped by all variants of Labyrinth Warrior.
- Found in Chalice Dungeon chests and corpses.
- Sold by the Insight Bath Messengers in NG+ for 3 Insight.
- Used to create Rotted Offerings for depth 5 Root Chalices.