The inner mouth is one of the most iconic physical features of the species Xenomorph XX121. It consists of a piston-like tongue tipped with a secondary set of jaws located inside the creature's mouth. Xenomorphs are capable of extending their inner jaws with ferocious speed and force as a means of attack, and it is in many ways their signature method of killing their victims. The Moray Eel has a similar mouthpart, called a pharyngeal jaw.