Jelly Slimes

Minecraft has had the same 2 Giant Slime mobs for so long! There is the Slime and the Magma Cube. But what if we could add another one? Maybe Minecraft could add a Jelly Slime that spawns in the water, can swim, and drops Jelly which can be used for crafting. And it doesn't stop there. We can add other Giant Cubes that spawn all over the world, and there would be different biome variants. The point is, in the Game of Blocks, there are not enough cube-shaped mobs. Please add more!