An aspis (ἀσπίς), sometimes also referred to as a hoplon, was the heavy wooden shield used by the infantry in various periods of ancient Hellas. Ancient Hellenic aspides (ἀσπίδες) featured a huge assortment of incredible designs, ranging from Hellenic symbols of myth to fearsome animals, all designed to make a shield more personal and more intimidating. Every city-state had its own design (or several designs, depending on the time). I found this very interesting video about the use of the shield and I thought you might like it as well.