No Hit Boss

The no hit boss challenge consists in defeating any Boss taking no damage. This gives an additional chance to obtain some Primordial Fragment.

Boss	Primordial Fragment Reward
Corrupted Gundyr	1 Primordial Fragment (25% drop rate)
Vordt of the Boreal Valley	1 Primordial Fragment (25% drop rate)
Aborr	1 Primordial Fragment (25% drop rate)
Curse-rotted Greatwood	1 Primordial Fragment (25% drop rate)
Crystal Sage	1 Primordial Fragment (50% drop rate)
Cathedral Guardian	1 Primordial Fragment (50% drop rate)
Deacons of the Deep	1 Primordial Fragment (50% drop rate)
Abyss Watchers	1 Primordial Fragment (100% drop rate)
High Lord Wolnir	1 Primordial Fragment (50% drop rate)
Old Demon King	1 Primordial Fragment (75% drop rate)
Pontiff Sulyvahn	1 Primordial Fragment (75% drop rate)
Aldrich, Devourer of Gods	1 Primordial Fragment (100% drop rate)
The Lordran Remnants	1 Primordial Fragment (100% drop rate)
The Fallen Protector and the Fair Maiden	1 Primordial Fragment (100% drop rate)
Yhorm the Giant	1 Primordial Fragment (75% drop rate)
Dancer of the Boreal Valley	1 Primordial Fragment (75% drop rate)
Oceiros, the Consumed King	1 Primordial Fragment (100% drop rate)
Twisted Knight	1 Primordial Fragment (100% drop rate)
Dragonslayer Armour	1 Primordial Fragment (100% drop rate)
Ancient Wyvern	1 Primordial Fragment (25% drop rate)
Trio of Explorers	1 Primordial Fragment (100% drop rate)
The Nameless King	1 Primordial Fragment (100% drop rate)
Champion Gundyr	1 Primordial Fragment (100% drop rate)
Mirror Knight	1 Primordial Fragment (100% drop rate)
The Twin Princes	1 Primordial Fragment (100% drop rate)
The Marauder	1 Primordial Fragment (100% drop rate)
Soul of Cinder	2 Primordial Fragment (100% drop rate)
Prince Dorthinus	1 Primordial Fragment (100% drop rate)
Princess Yngvil and Dearest Akseliane	2 Primordial Fragment (100% drop rate)
Sister Friede	1 Primordial Fragment (100% drop rate)
The Demon Prince	1 Primordial Fragment (100% drop rate)
Darkeater Midir	2 Primordial Fragment (100% drop rate)
Slave Knight Gael	2 Primordial Fragment (100% drop rate)
Halflight, Spear of the Church	1 Primordial Fragment (100% drop rate)

Notes

• The drops rates don't stack with their normal drop rates or the ones from the Curse of Valor, they are a chance to obtain additional drops besides those.
• Build up from Status Effects from attacks like Vordt's forst aura or Soul of Cinder's poison cloud will not invalidate the attempt.
• Death or character save file reload will reset a failed attempt.
• Enemy Revival can be used to reset the challenge whether the previous attempt was a success or not.

Information here is accurate for version 2.15.