Deep-Kin

Origin
"It was a tall, gaunt creature, hunched over, covered in scales. Its arms extended well below its knees, ending in webbed claws with foot-long fingers. The fin on its back seemed to quiver like the lure of a rattlesnake. Its large eyes...round, black, pupiless...were filled with a malevolent light. It opened its mouth, filled with fangs the size of carpenter's nails...and let loose a screech filled with hatred. I would like to say that the noise was inhuman...but it wasn't. It was far too human for something...so alien. So I ran...and that creature killed my friend." -Georgia H. Richards, testifying at her trial for the death of Shirley Prince, 1904.

The Deep-Kin are an (apparently malevolent) aquatic species of fish-like humanoids. If reports are to be believed, they are carnivores with a taste for human flesh that prey on isolated settlements. Some theorize that perhaps a solitary Deep-Kin was the real "Jack the Ripper", with any account that conflicts with this theory cast as lies formulated by the British crown. Intrestingly, researchers have discovered Nazi documents from shortly before Operation Barbarossa speaking of the relocation of some troops from the operation in order to deal with "Fische-Männer", i.e. Fish-Men, that were supposedly causing havoc at secret research facility.

Powers
Deep-Kin are amphibious, possess excellent swimming capabilties, can see in total darkness, and their scaly bodies can be tough to injure. There are also rumors of giant Deep-Kin that tower over 30 ft. tall or more.