Kalmar "class Cephalopoda" tana nufin nau'in haraji na dabbobin ruwa wanda ya hada da dorinar ruwa, squids, cuttlefish, da nautiluses. Membobin wannan ajin suna da halin samun kansa na musamman mai ingantattun idanuwa da baki kewaye da tanti ko hannaye. Hakanan suna da rufaffiyar tsarin jijiyoyin jini da tsarin juyayi mai rikitarwa, wanda ke sanya su wasu daga cikin mafi kyawun invertebrates. Cephalopods an san su da ikon canza launi da rubutu don kamanni, da kuma iyawarsu ta musamman na squirt tawada azaman hanyar tsaro.