H.P. Lovecraft - Shoggoth

"Formless protoplasm able to mock and reflect all forms and organs and processes - viscous agglutinations of bubbling cells - rubbery fifteen-foot spheroids infinitely plastic and ductile - slaves of suggestion, builders of cities - more and more sullen, more and more intelligent, more and more amphibious, more and more imitative! Great God! What madness made even those blasphemous Old Ones willing to use and carve such things?"
-H.P. Lovecraft, "At the Mountains Of Madness"

Shoggoths are amorphous, shapeshifting beings. They were genetically engineered by the Elder Things as a race of servant-tools, but eventually rose up against their masters and drove them to extinction. Shoggoths are now found in isolated locales across Earth.