Box jellyfish
Although the notoriously dangerous species of box jellyfish are largely restricted to the tropical Indo-Pacific region, various species of box jellyfish can be found widely in tropical and subtropical oceans, including the Atlantic Ocean and the east Pacific Ocean, with species as far north as California ("Carybdea confusa"), the Mediterranean Sea ("Carybdea marsupialis") and Japan (such as "Chironex yamaguchii"), and as far south as South Africa (for example, "Carybdea branchi") and New Zealand (such as "Copula sivickisi").
Chrysaora achlyos
The black sea nettle (Chrysaora achlyos), sometimes informally known as the black jellyfish or sarlacc jellyfish, is a species of jellyfish that can be found in the waters of the Pacific Ocean. Its range is thought to be from Monterey Bay in the north, down to southern Baja California and Mexico, though there are reports of sightings as far north as British Columbia.