DO NOT attempt to kite these with an Argent, I almost lost my best mount to one because we couldn't fly fast enough to get out of its attack range. If you run into one, my best suggestion is to turn tight circles as you fly up, which thankfully I figgured out with just a sliver of health left.
I guess I'll save the kiting for my best pteranodon from now on.
If you have access to a snow owl, you can tame these with any crossbow! Just shoot it until it looks bloody, and heal it with the snow owl’s ability. Do it so that it heals quite a bit, but not so long that the torpor drains back empty. Then hop off the owl and continue shooting it with tranq arrows. I knocked a 140 with a 279 crossbow and using this method it had over half hp remaining once it finally went down. Help this get to the top!