Puffler: The size changing underwater transport mount

They would be small fish (at first glance) that appear like a pufferfish minus the spikes and a rainbow of colors to chose from. They would live in small coral bundles that had small holes for them to get in the coral. Inside the coral would be a "coral bed" a block that looks like a bundle of differnt coral fans. it would go here every so often, sleep a little then go explore. To tame it you would give it a coral fan. It would run into it's home and "add the fan to it's home" showing happy villager particles. give it enough coral fans and  it will be tamed. what this seemingly small fish can do is expand by sucking in water then blowing it out to push away enemys. you can make it an artifical home by combining glass in a cauldron shape then one coral fan in the middle. you can bucket it for transportation. when unexpanded it is 2 blocks long 1 block wide, when expanded it is 6 blocks long 1 block wide. when expanded it can fit six people and when unexpanded it can fit 2 people. it's slow but, can store as much as 2 big chests. if you feed it seaweed it can breed by laying eggs in its bed. periodicly they shed scales that can be used as a replacement for pufferfish in a waterbreathing potion. if fed a dye it will change it's color. it also give waterbreathing to it's riders and can blow bubbles to give air to it's surounding friends. it can not do any real damage though because, they are very friendly. the babys can be put on your shoulder as sort of a "underwater jetpack".