Squids have three hearts. Squids are part of the class of animals called Cephalopods, and almost all of these creatures have three hearts. They also have blue blood.
Two of the squid's hearts, called the brachial hearts, pump blood just to the gills, which helps keep the oxygen moving through the squid's body. The third heart, called the central or systemic heart, pumps the blood throughout the rest of the body. This heart is further divided into three chambers: two auricles and one ventricle. The squid's hearts are greenish in color and are in very close proximity to the squid's excretory system.