An itchy is easier to tame than most neutral/passive creatures. It naturally approaches to you if you swim close to it, but it will never make a move to attack, allowing safe feeding so long as there are not predators.
Technically you can get a bunch of these to come to the surface easily with a pelagornis, and fly away if a megalodon attacks, if you get enough it might even become harder for megalodons to hit you lol
Best for killing scorpions on bottom of ocean floor since they don't take torpor. Scorpions down there will knock any other animals out. Once you kill it, hit it with a pickaxe to gather black pearls. Very useful for the next update with tek gear.