These are GREAT for chitin! Just ride an Argentavis and grab them with the talons! Then find a safe place, go close to the ground, and attack it mid air. Then go to the ground, and harvest with metal hatchet. No damage taken, a lot of chitin gathered! I have found them most commonly right on the southern border a tundra winter zone of in a jungle.
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.