Nightmare Catcher is a Mythical material used as a crafting and upgrading ingredient for specific late game content. Its rarity makes it a valuable resource to keep.

Obtainment:

The Nightmare Catcher is obtained by defeating Reborn Skeletons and Living Zombies, both of which have a chance to drop the material. Since it is a Mythical drop, farming may require multiple kills before one appears, so players should be prepared for a grind if they need several for crafting.

Usage:

Nightmare Catcher Is Used to Upgrading Fruits.
Blox Fruits:

Pain
• Torment Conductor 1, 6,000, 5
• Spectral Assimilation 3, 9,500, 5