I tried to say 'wild like an animal' to make a distinction from the familiar concept of a 'wild animal'.

A wild human animal is not domesticated and does not care about what society thinks is normal acceptable behavior. It treats feeling as equal with reason; both mere qualia to be either utilized or disregarded...

I'm sure naturalists will gladly heap entire dictionaries of verbage on what I'm trying to communicate: all explainable in an instant by an upredictable, fundamentally not-safe look in one's eyes.