Defeating the Kraken would make it possible to breathe underwater in the Abyss. This can be combined with glass to make a Kraken helmet, and also can be used to make other diving items. When defeated, it drops 10-15 Kraken leather. It can be summoned with a Kraken doll, which is 1 diamond in the middle of the crafting grid, and a leather in each of the corners. It would be a super-sized, and far more powerful, version of Mob A from Minecon Earth. There is also a new boss in the ocean called the Kraken. This would make going through the abyss more efficient, however it's far more dangerous. In the Abyss, this ratio would be 1:16, compared to 1:8. The Nether has a feature where for every block you travel in the nether, you have traveled 8 in the overworld. Going through the portal will create a new portal in the abyss dimension at 255. This gives more reason to explore the ocean in 1.13. It's lit by right-clicking the frame with a heart of the sea.
A dimension deep underwater, which can be accessed by placing 12 blocks (Abyss portal blocks) in the arrangement of the end portal, and these blocks can be crafted by placing coral blocks around a nautilus shell in a crafting table.
