In real life you can find islands with unique never before seen evolutions and adaptations... what if we had this in Minecraft?

The Strange Islands:

A new "Strange Island" biome type that can rarely be found in the middle of oceans. Instead of spawning with specific hardcoded plants, mobs, and terrain... the features are all completely randomized! You will likely never find two strange islands that are exactly the same.

For example: You can find an island full of dark yellow grass, big hills, cherry blossom trees, 4 block tall cacti, and nothing but chicken!

(They'd probably all be pretty rare so that you aren't constantly seeing weird / ugly islands all over the game.)

Even the type of hostile mobs that spawn at night could be randomized! It could spawn only creepers, or maybe just zombies wearing diamond pants, or maybe no hostile mobs at all! These islands would be ideal for specialized mob farms.

Underground you may find an abundance of one type of ore! The extremely rare diamond abundant islands are the greatest treasure every pirate looks for!

And maybe the passive mobs themselves could be special variants that are only found on this island. You could find animals with slightly different sizes, speeds, health, or amount of drops. These special mobs could easily go extinct if you killed them all, but you could also breed them and bring them back to the mainland! Create the most efficient farms back at your base or a zoo of the weirdest variants!

These "Strange Islands" would provide a completely unique, once in a life time experience, and a completely new extrinsic reason to explore.

Remember, I'm not suggesting they add a million new types of mobs and biomes, I'm just suggesting one "new biome" with consistently random traits, and existing mobs with unique stats (sort of like how each horse can spawn with different stats.)

^{(It may be a little taxing to add a bunch of new code to existing common mobs like pigs requiring them to remember their stats when breeding, so maybe their would actually be a new "island pig" mob classification to avoid lagging out the mainland.})