Crimson Serpent Card card_broken_lighthouse_2

Card Rare drop

What it is for

Card: fits into Body gear that has a free slot.

Armor element Poison.

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

The best source is Crimson Serpent, at 0.050% per kill. You can farm it at Broken Lighthouse.