As you can see in this shot, moray eels have sharp teeth. In actually, they have two sets of teeth, the ones you can see here and another set hidden in their throat. The set of teeth that are in their throat allow them to break up food and digest it. Kinda sounds like the stuff from a horror movie!
Moray's don't see well, but they have an excellent sense of smell, which they use to help them locate their prey. They prefer to hunt mostly at night. Overall, they tend to be shy and prefer to flee, rather than fight. However they will attack if threatened or someone approaches their den too closely. This one isn't getting ready to attack. The moray it breathes by opening and closing it's mouth as a way of passing water through it's gills, which is the behavior you are seeing in this image.