Synonyms for Massasauga (same or very similar meaning)
WordNet sense 1 (small pygmy rattlesnake):
ground rattler, Sistrurus miliarisWordNet sense 2 (pygmy rattlesnake found in moist areas from the Great Lakes to Mexico; feeds on mice and small amphibians):
massasauga rattler, Sistrurus catenatusFrom the ODE community, based on WordNetadd/edit