Step 1. Get 2 takes wth over 2,000 hp just to be safe
Step 2. Put the tames on passive but have them follow u
Step 3. Have the tames tank the hits while u start tranqing
Step 4. Wait until the rexs torpor is less than 100 then put food in it u shouldn’t need any narcotics but take some just in case

It’s pretty eastern just use a bloodstalker

Just walk up and passive tame it with prime meat

If you have your menu out while taming, bugs will not spawn to kill you.

To breed them without lava enable mating and continuously hit them with wyvern fire Get this to the top I have 6 so far