The Mighty Ender Chicken is an alternative boss to the Ender Dragon. It’s a massive beast and very difficult to kill. All you need is 8 obsidian blocks and a diamond block to spawn it by dropping an egg on the platform.
It’ll take some time to hatch from that egg then get ready because this chicken will leave a path of destruction wherever it goes.
This one looks similar but wreaks significantly more havoc on your world and takes longer to hatch from its protective shell leaving you incapable of damaging it!