VII Cults (for instance, Dagon and Hydra) The deep ones have great skill in biology and genetics, and thus can often control and direct such growth to suit their nefarious purposes Deep ones are also capable of domesticating and using other types of undersea creatures, particularly Mythos beings such as shoggoths Interaction The deep ones maintain constant surveillance and contact with the surface world near their homes Their ultimate purpose is not their prerogative, but determined by Cthulhu’s design They not only monitor mortal activity for the Great Old One, but may someday be used to supplant the mortal realm Their hybridization and inbreeding is one important tool toward that goal, for it allows them to blend in with mortals The hybrids, of course, knowing they will one day be full deep ones, are fully supportive of the deep ones’ goals Deep ones are known to have originated many magic items, including the medallion of Y' Nthlei, seal of Hydra, starstone of Mnar, and tiara of Mnar They also practice a profoundly dangerous method of creating twshas to control shoggoths and proto-shoggoths 197