Coop de Grâce is a Unique Two-Handed Slashing in Diablo IV Season 15 for All classes. It comes from World drop: any Unique source - Helltide, Nightmare Dungeons, The Pit, Whisper caches, Infernal Hordes, Undercity, Purveyor of Curiosities gambling (3.2.1: "All Unique items are now available to drop at level 1, and in any Difficulty").
Unique power
Lucky Hit: Damage to Injured enemies has up to a [10 - 15]% chance to spawn a flock of explosive chickens.
Affixes
Lucky Hit: Up to a +[8.8 - 20.0]% Chance to Execute Injured Non-Elites (8.8-20.0)
+[42.0 - 70.0]% Damage to Injured Enemies (42.0-70.0)
+[9.0 - 24.0]% Critical Strike Chance Against Injured Enemies (9.0-24.0)
+[259 - 340]% Damage to Poultry (259-340)
Where it drops
World drop: any Unique source - Helltide, Nightmare Dungeons, The Pit, Whisper caches, Infernal Hordes, Undercity, Purveyor of Curiosities gambling (3.2.1: "All Unique items are now available to drop at level 1, and in any Difficulty")