Over world bat boss

There should be a boss for the over world because there is one for the other two dimensions as well. This boss would be based on the bats that fly around the over world at night because so far bats are ultimately useless. The way this would work is that rarely you may see a large flock of bats(an amount that you would definitely notice, about 20 really close together) that are always flying in the direction of a large cave structure. In this structure would be where the bat boss lives. The bat boss would be a large version of a bat, that attacks you as well as summons a large quantity of bats to obstruct your vision and hits. When you defeat this boss you are given a large amount of XP and a portal opens up(like how the end city portal opens after you defeat the Ender dragon.) that leads you to a large and open underground area where you would find a really big cave city that you can find chests with valuable items in them. The reason for this idea is because we need more bosses and the bats still have absolutely no use.