Ender dragon

Ender Dragon usage

This update concept could have the ender dragon egg be hatch-able, as well as having the hatched ender dragon be a rideable mob. A special type of harness could be used to ride it. This harness could be a rare item found in end bases, or could be an expensive crafting item, maybe using an elytra as one of the ingredients. Perhaps a new achievement could be introduced as well, something along the lines of "Taming the beast" or "Infamous associate" or whatever. 

This feat would be an end-game achievement, (At the point where the player has completed all major and side tasks) and would have to be very difficult to accomplish, since it would be a significantly effective form of travel (prolonged flight) and combat (Dragon breath and fireballs).

It could have a flight cooldown period, where the user has to feed it to regain energy. Perhaps copious amounts of chorus fruit. (A visible energy/flight bar could be shown above the user's hot bar when riding)

I'm sure several mods have been made including similar mechanics or features, but I think it could be a cool addition to the game.