Just get a few spears, then stab them in the head while slowly walking backwards. If your brave enough, us a club to knock them out. But if you don’t want two-thirds of your health gone, use tranq arrows.

Give it food or get food for it.

Give it food or get food for it and dot hit it.

Before knocking out a turtle to tame it, magnifying glass it to see the base health so you know that you will get a good health turtle.

The carbonemys can be knocked out with a metal pick/axe. This makes it easier than wasting narcotics and arrows just to knock it out