Minecraft wiki entry for Armor, associated text: Zombies, skeletons and their variants that spawn with armor have a small chance of dropping their armor when killed by the player. When killed, the armor they drop can vary from 0 to full durability. Upon death, zombies, skeletons, zombified piglins, and wither skeletons always drop any armor that they picked up and equipped. They may also be wearing enchanted armor that retains the enchantment when dropped.