Project Nemesis is a fan driven website for games that use the One-Roll Engine (like Nemesis, Wild Talents, Reign and Monsters) or Chaosium's Basic Roleplay System (BRP) (like Call of Cthulhu) and the Delta Green setting.
Deep Ones are aquatic humanoid creatures that worship Cthulhu and his ilk. They infest and interact with degenerate seaside towns, crossbreeding with local populations to produce hybrid Human/Deep Ones and spread the worship of the Great Old Ones.
Here are some Dreaming rules that again didn't make the final cut of Nemesis becuase I was too late in submitting them. I'll happily admit they were inspired by questions posed by Agent Donald on the DGML and Yog-Sothoth.com.