Volibear E bug ?

Ok so jungle goes up to grump /red /blue and if he uses his E - Majestic Roar without damaging it first with anything else, the creature starts running around -feared. starts hitting it with basic attacks but the creature is healing up back to full until the fear runs out. Keep in mind E also dmges. This does not happen on chickens. Will need to test it cuz this "testing" was from a game i played.

I dont think its intended to work in that way.