Chainmail Chestplate

A chainmail chestplate[a] is an uncommon variant of chestplate that cannot be crafted, and is only obtainable through other means such as trading. It is the fourth-highest tier of chestplate, having the same armor points as a golden chestplate but with higher durability.

Zombies, husks, skeletons, strays, and bogged have a small chance to spawn wearing armor. There is a 8.5% chance (9.5% with Looting I, 10.5% with Looting II and 11.5% with Looting III) for the mob to drop the chestplate they're wearing upon death unless they are spawned from an ominous trial spawner. The dropped chestplate is usually badly damaged, and may be enchanted with enchantment levels 5-19.

In Bedrock Edition, naturally spawned armor worn by a zombie has a 100% drop rate when a zombie is drowned.