Opisthoteuthiscaliforniana, also known as the flapjackoctopus, is a species of umbrella octopus. Their maximum size is 20 centimetres (7.9 in) mantle length. They have eight jointed legs which are affixed together in an umbrella shape and have a gelatinous body, which spreads into a parachute shape when manoeuvring through dimly lit water.