Instrument: Mouth

From the journals of Dr. Johannes Krug:

In my traverses I have seldom come across such intriguing creatures as the ones I am next going to introduce to my readers. Truly remarkable faunae!

Vreth , as I recall correctly, seems to be youngest of this pack, but commands a certain amount of respect nonetheless. By voice alone, I presume. Its girth is equal to less than half of its more robust fellows, but yet somehow an unearthly scream develops within this strange life form. Stunning the prey with an aural overload Vreth quickly finishes its victims. I'm simply puzzled. Its insides simply shouldn't have the volume necessary to procure such a massive and ugly noise. I must get a chance to dissect this one.