Chiropsalmus quadrumanus
Chiropsalmus quadrumanus, commonly known as the four-handed box jellyfish, is a species of box jellyfish found in the western Atlantic Ocean, the Gulf of Mexico and the Pacific Ocean. The sting is venomous and dangerous to humans, especially children.
Linuche aquila
Linuche aquila is a species of cnidarian found in the tropical and subtropical Pacific Ocean. It is very small and is commonly known as a thimble jellyfish because of its size and shape. The larvae can cause bathers to develop an itchy red rash commonly known as Seabather's eruption.