CV 3 has an enemy more annoying than medusa heads, and less annoying than the loop 2 skulls, the bone dragon cannon pillars. There's parts of the game you must climb, these things are strategically placed to eat your health away while your fighting off another cannon.
Edit: Medusa heads in the original Akdra X68K (the original mode on PS1's CV Chronicles, though not sure if the difficulty is as high as the original X68K version) clocktower were a massive pain, though the gear wheels that would roll to you and from you were more painful.