- Cyclops - (Greek mythology) one of a race of giants having a single eye in the middle of their forehead
--1 is a kind of giant
- cyclops, water flea - minute free-swimming freshwater copepod having a large median eye and pear-shaped body and long antennae used in swimming; important in some food chains and as intermediate hosts of parasitic worms that affect man e.g. Guinea worms
--2 is a kind of copepod, copepod crustacean
--2 is a member of genus Cyclops - cyclops, water flea - minute free-swimming freshwater copepod having a large median eye and pear-shaped body and long antennae used in swimming; important in some food chains and as intermediate hosts of parasitic worms that affect man e.g. Guinea worms