Cookiecutter Shark, Isistius brasiliensis

So I personally find this creature to be truly strange and frightening. It is known as a Cookie cutter shark! It is considered a parasite. This small deep sea shark's jaws allow it to remove circular plugs of flesh from its victims (check out the picture).

 It also has a pale blue-green bioluminescent belly which, when viewed from below, makes it blend into to the ocean surface above.

  

a.k.a., Cigar Shark, Luminous Shark
Honestly, I dont know about you but I am sure glad that they are deep sea sharks!