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.
Full Ghillisuit, bug repellent, and balls of steel because these are scary to tame! They have the taming slot right behind their head about where the saddle would normally sit. Must approach from behind and only approach when feeding, stay away otherwise
Dodo is wrong about amount of tranq arrows needed (crossbow). Lvl.19 arthro, it states 1 headshot or 3 hits. It took me about 15 and it died, thankfully. Boy did I freak out after the fifth arrow... I was running naked in the woods
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.
I find the best way to knock these out and tame them is to simply lead them into the water and grapple to them and they instantly de-aggro and it’s just a matter of feeding it. It has worked many times. Also no ghillie or bug repellent required 👍