AWKWARD ZOMBIE

I'm trying to do stamina loss only for the Cobra Unit but The fear is getting to annoy me because he actually eats

Throw a bunch of poison food around and he goes for it (mushrooms, dart frogs). He'll barf after eating and be open.

Also, apparently if you take a fake death pill he'll gloat and then turn his back on you

Plus it helps to use thermal goggles while he's in the trees so you can get more hits in. Make sure to cqc him when he comes down for food. He'll prioritize whatever food you yourself drop so make sure to put it close to you.