Proven to be a difficult foe to tame on foot. My preferred method is to make a Dino gate, a hallway of windows, then another gate on the other side. Have a naked friend attract it to the cage and get it inside, while you close the door and proceed to knock out the theriz with whatever you have. Higher levels will be a pain to take down. If your cage is wood, take down the theriz as fast as you can because he/she will destroy it decently quick. Another useful tip is that it's health and damage go up more than average when you hit a new lvl with a tamed theriz.
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😂
I just tamed a lvl 20 theri and it took 1hr and 200 narcotics. This thing was a pain in the bootycheeks to tame but well worth it. It gathers a crap tone of berries, rare flowers, rare mushrooms, and also a good amount of thatch/wood. I recommend having around 50-70 tranq darts if you want to knock out a high lvl theri.
Use stone building 4 foundations with door frames all around perimeter and 2 walls high. On outside place stairs on one side- this will be the side it chases u up. Once it’s in the trap knock it out with tranq arrows.
Recommend have berry gatherer with u- need A LOT of narco.