Putrid Surge is a spell in the Blood Magic category. Upon reaching 15% or lower health, it will cause a wave of toxic blood to erupt from the player in all directions, causing toxic buildup and high poise damage in a high-range circle. This can be useful for taking on crowds or enemies that are very aggressive, but the spell also grants healing similar to that of a Soothing Herb, though less health is granted in total.

Found in a chest on a small outcropping in the Vile Canyons, surrounded by Blood Beetles.