[X] Beat him until he submits. Your instincts probably know more about how this race works than you do, but hold yourself back. All you really need is a display of dominance to make sure he doesn't ever think you are an acceptable target again.
[X] Reassure the thing you are not going to eat it or turn it in, You just want to ask some questions, if it's helpful maybe you can even find it some lizard to eat... The 'grot' does look awfully malnourished and even seems a bit childlike, you pity it.
[X]Give in to your instincts. It's the only way to make sure he can't threaten you again. It's ruthless but it makes sense. Bash him good and eat the delicious meat from his broken skull...wait what?
[X]Punt the annoying thing away with a good kick, your instincts are telling you this is the correct response to dealing with this 'grot' servant race when not hungry enough to eat one. And that it wouldn't permanently injure the thing.
[X] You were a doctor. You saved many lives during your life with your deep knowledge of the body and innovative ways of treating diseases and injuries. In many cases, you even improved the body with implants and prosthetics.