Echoing Skull Card card_bone_steppe_1

What it is for

Card: fits into Left hand gear that has a free slot.

Damage taken from Undead −35%.

Weighs 2 of your carry capacity — and weight is what stops drops once the bag fills up.

The best source is Echoing Skull, at 0.050% per kill. You can farm it at Bone Steppe.