This creature is either your best friend or your worst enemy. I recommend hammering speed, damage, and health. If tamed, it is a great early swimmer and good at helping tame other creatures. It doesn't make much noise so it can easily sneak up on you. Run away and shoot with tranq arrows. If you get stuck in it due to jumping or lag. Well. You can kiss you're butt good bye.
These guy's are pretty easy to outrun, but they are relentless! You'll have to get about 20-30 foundations' length away to lose aggro. Also don't let it sting you even once, you'll be down in seconds! They don't have a lot of health (one shot from a cross and they die are become extremely wounded) and most mounts can take care of them without a struggle. Stay safe Survivors!
If your an early player use a bola to stop it, then go to its side to avoid it's pinchers and stinger. Stab them to death, or you can knock them out with fists, a club, or bow and narc arrow. You can do this for taming or if you just want to safely wail on it
I was able to tame a Lv.60 Pulmonoscorpius in the Lava cave but the entrance was too small to bring them out; however, if you have an Argentavis you can grab them from the entryway and pull them out. Work for me.