Some interesting facts about Moray Eels include...

They have 2 sets of jaws

• They attack there victims with a hidden set of teeth for extra lethality
• Outer Jaws grasp the target while the inner set of teeth pulls the prey down its throat

Roughly 200 species

• Some species like the Zebra Moray have blunt teeth for dining on hard shell prey such as crabs, clams, mollusks, etc

They are nocturnal

• These Eels happen to be nocturnal meaning they are active when the sun sets and take night time swims

Source: mentalfloss.com