It took 14 track darts to the head to knockout. It took about 600 narcotics (I had to borrow from someone at a point) and it took about 3 hours (it was level 10)
They are amazing for wood, and since beavers are hard to find, these are worth it for wood.
Easy to knock it out, harder to tame it. I tamed two theris and mated them, i got twins and i was very happy. Taming it its very hard, in order to knock it out, be at a high rock, then get tranq arrows then knock it out.
If this dino spawns near your base and you are low and mobile player then just do one thing. Put your all stuff in your base and go near the dino then run in opposite side of your base and lead him to far away from your home before he destroy all you have even your pets. just don't uninstall the game bcoz of this😂