Moray eels have a strong sense of smell and use it to ambush their prey. They have a large jaw and their mouth is camouflaged on the inside.
Their second jaw is located in their throat, because their heads are too narrow to create the negative pressure most fish use to swallow their prey.
Their second jaw does have teeth. When they catch their prey, their second jaw shoots into their mouth to capture the prey and pulls it down the throat and into the digestive system.