This guy has the weirdest tame in the game! You thought that getting creatures eggs to hatch and tame them was unique, say hello to this guy. What you have to do is to lure a fish swarm near it and let it eat them. I would recommend leaving render distance while doing this because no bad things will come and mess up the taming progress.
DON'T BOTHER DEFENDING THE TURTLE FOR 30 MINUTES!!!! Lure the swarm to it and then just leave render... If no one is near the turtle while the swarm tames it nothing will bother it and it'll tame out on it's own... EzPz
Ps: If ANYONE is in render it won't work, so wait until pop is real low to use said strat.