Deeper and more diverse oceans

This idea is like many others that people had, but it should be way deeper with hundreds of blocks of depth better generation at the bottom to avoiding that same plain green. Implementation of actual world generation for sand bars, depth, new blocks, and new creatures such as an aquatic version of a happy ghast I propose as a turtle that could have blocks out onto it. New creatures for bottom of oceans that are more for a decorative purpose similar to axolotols or frogs where they could give a new block. This would be implemented as a major update like caves and cliffs to spruce up a un explored