This music video features moray eels and snake eels from the tropical Pacific, filmed in Guam and the Philippines. Quite appropriately, it is set to the song "The Dragon" by The Calm Blue Sea (with permission).
Fearsome countenance. Serpentine form. Menacing fangs. Dragons, indeed.
Despite their snake-like appearances, eels are fishes...predatory bony fishes, with reduced gill openings, and dorsal, anal and caudal fins fused into one long fin running the length of the body. Most feed on fishes, octopus and squids with sharp knife-like canine teeth, while some (like Echidna nebulosa and Siderea thyrsoidea) crunch crustaceans with short conical teeth.
Snake eels lack scales and have a hard, pointed finless tail tip that they use to burrow backwards into the sand where they lie in wait for their prey, rarely emerging fully.
Most eels are more active by night. While frightening in appearance, eels are typically docile -- but can inflict serious injuries when threatened.
Here be dragons.
Reference: Myers, R. F. 1999. Micronesian Reef Fishes. Coral Graphics, USA.