Leather Harness of Animal Slaying

is one of nine powerful Ephemeral Relics that can sometimes be found in different areas in New Britannia. These items are Pet Equipment items that can be equipped by Tamed Pet or Summoned Pet creatures.
 * The Companion Physical Resistance item effect value will be different for all players. This value is possibly related to the players Adventure Level.
 * Item properties updated as of Release 112.

''This leather harness is embossed with glowing pictograms depicting many animals such as bears, wolves and boars in various death poses. This extremely rare and powerful Ephemeral Relic cannot be repaired and features a very low durability, so this item can only be utilized for a short period of time before it is fully depleted. Once depleted, salvage this item for potentially valuable crafting materials.''

Found
This item is rumored to be found somewhere within Ulfheim, Jotungrund, Grannus Colossus and Ruins of Utheim...