Maybe you could add a new boss?

Adding a new boss that has a small chance to be tamed would be fun because it adds something that people can look forward to when facing this boss, I think it would be cool to make the boss some sort of dragon because then it could have lots of different attacks and abilities, like one for each element: Earth, Fire, Water, Air. They could have different strengths and weaknesses depending where you summon them, E.G. Summoned on a mountain: Flies very fast and is known for speed, but doesn't have much health. Summoned underwater: Swims fast and is stronger in water, but is weak to fire and isn’t the best at flying (like a leviathan only with wings and it can go on land). Or it can be summoned in different worlds like in the Nether, where it would be specifically based on fire and earth and stronger near fire and able to swim in lava as fast as someone using an elytra; and if they are summoned in the End, then they could be based on the sky, and, like an enderman, able to teleport. They would be able to teleport and is three times as fast as someone using an elytra when it’s in the end. This addition to the game would be very fun since it means that you would have a boss able to be tamed and gives you something to prank your friends with.