This might be hard to put in use, maybe impossible without an hour or so of modding:
A titan Arena: twice a day, a Titan will spawn. A Titan is a giant freaking zombie. theoretically, they are quite, meh, easy to beat, cause basically, it's a zombie, you can stay in one place just spam sword, not that it's any different from the dragon's second phase where you just wait to shoot it. So, to balance that, Zombie spawners.
The Titan Arena could either spawn the Titan alongside the dragon, in terms of the time (aka the end regeneration time) or instead, spawn in the the opposite time(e.g the dragon spawns at 12 am/pm, the titan will spawn at 6 am/pm).
Or we can spawn him 4 times a day, depending on the popularity, the point is to give another option of a small boss, the Titan shouldn't bring much exp, nor is he supposed to have much drops either, BUT with a little modding, we could maybe give the Titan a little surprise for the players to make him worthwhile: a 10% chance to drop a Zombie head!
Why do you ask? This is indeed a smart and commonly asked question in general.
It's a little reward for the players, a small option to experience something they can't really get in solo, sure everyone can go slay a dragon alone, with a little effort. spawning a Wither, somehting else, but still. but a Titan? now that's something you don't see everyday.
Aside from that, it can be fun, something like a daily event people could wait for, it can also lift up the economy a bit with the zombie head drop. If we manage to make it hard enough, people could go in parties of 2-3.
Another option which I'm unsure of, Zombies can wear armor, the question is whether the titan can, and if so, surely he could wear a sword.
As for the arena itself, if interest will be shown in the idea, and it will be possible, I can build such arena, it's mostly flat so the Titan can move, and it should have a spawn room separated so the zombies won't camp xD
As for the area/place, we surely don't need another world for such thing, we can use the same place the Wither uses.
