More Bosses!

1. Hermite - Crab Mob - It waits in the water for a player or other mob to swim past around the shores. It uses its gigantic claw to catch hold of players and pull them underwater. If you defeat the Hermite then it drops its crab claw which you can use as a weapon to grab your enemies. It has damage of 1 heart every squeeze. 

2. The main man - Herobrine - He can lightening strike, he can shoot fireballs, he can fly and he has 600 health! It is so worth it when you defeat him because you can ban operators and you have all his abilities. 

3. Deepcrawler - A worm like mob - spawns in Plains/forest/jungle/taiga/underground biomes. It is triggered by movement when you dig 5 blocks or more underground. It has maze like tunnels. If you can find the centre then you will infinite diamonds. It can burst through earth and stone blocks. It can knock players back which deals similar damage to falling from a height. If you defeat it then it drops an earth drill which can drill through earth, stone  and bedrock blocks. 

4. The Witherstorm - It is not only big, it's not only strong, it can pretty much take over and corrupt your world! So you ask about this mythical creature...it was born by a scientist, but he made a mistake. He put a command block instead of a soul stone and, boom! The dead scientist was in the structure but there was no witherstorm. This is a structure under villages, all that is missing is one wither head, but when you defeat it you get a command block. It is indestructible.