One of the easiest ways I have found to tame these guys is to deliberately get snatched and then knock it out. I have seen tips that talk about using your fists or club, but you can also use tranq arrows just fine.

Do note that you need a decent amount of health and preferably chitin armour or up. Though at some point when the Kapro would 'run away', it will also stop damaging you while you remain in its mouth. Then you do what you gotta do, which is shove meat down it's toothy gob!