Prohibiting Threatened and Endangered Creature Trophies Act of 2018 or the ProTECT Act of 2018 This bill amends the Endangered Species Act of 1973 to prohibit taking threatened species within the United States or U.S. territorial seas as trophies or importing such trophies. A trophy is a dead animal, or part of the animal, that was obtained under an authorization issued by a state, foreign government, or private landowner.