Hippocampus, the half horse/half fish sea creature of Greek mythology that pulled Poseidon's chariot; from hippo, horse and kampos, monster.
The Hippocampus. Graphic published in European Neurology 2005;53:171-178
The hippocampus is one of the first structures to show degenerative changes in Alzheimer's disease.
Hippocampus is also the genus name of the fish known as the seahorse.