Use the broth of enlightment, since it is their kibble. If you use a broth of enlightment a a balm it I a insta tame, since authors take forever to eat. You can find the recipe on google or something, be warned, it is EXPENSIVE.
Easiest and safest way to tame this is to lure it under water. They stop aggro and you can tame as you please. Just make sure you come up for air every once in a while. Also be sure the water is deep enough.