They didn't have a permanent hunting ground and sentient beeings would eventualy start to see pattern if he where to eat them and would compromise his future. To prevent such a future they chose a vegetarian lifestyle, they still very much ate and needed meat but think of it like a vampire who only feed on animals, they to only eat non sentient creatures.
They prowled, as the predator that they where, close to the ground, in the form of a black panther. They circled the fire, although the fire meant prey, it was forbidden prey, besides, fire was bad. Instead they circled the source of the fire, as if they where part of its shadow, until they where at a decent distance.
Back to the hunt, they jumped what movement they had tought to be real prey moving in the green foliage. They quickly backed of and shifted their form slightly to the side where another form would emerge, with tendrils acting like hair which is attracted to static electricity, from panther to human.
They looked at the other, their self imposed rule forbade them to eat it but they had instinctually shifted in front of them, which was against their self imposed rules of self preservation, of blending in. They observed it, tilting their head, should they greet it or kill it out of principle?