Picking a favorite Placodus illustration is actually quite difficult. I assumed that it would be simpler given that Placodus is a relatively simplistic looking marine reptile. However, despite its rather boring looking body plan, it has clearly inspired some rather interesting illustrations. Instead of going on about my favorites and why they are my favorites, here is the size comparison illustration and a nice study of Placodus by Dmitry Bogdanov. The size comparison shows how small Placodus actually was compared to the average human. Bogdanov's illustration shows Placodus from the side and in great detail.