Nether-Octopus?

So since there is a boss in the end (wonder dragon) there should be a boss for the nether too. What about a giant flying purple octopus that chases you across a designated area, and will hide behind a wall with a few hole, and shoot fire at you with cannons or something. It will also reach out and grab and/or hit you with its tentacles. It could also have some sort of way of healing like the ender dragon. There would be a designated area for this creature’s boss fight, and if you leave it, it’s health and stuff gets fully restored.