Helmets of all shapes and sizes. One thing that makes a helmet cool is a crest of almost any shape and size on it. History is full of Cool Helmets, from the Greek Chalcidian helmet worn by Hoplite to the Roman gladiators' ornate helmets to Japanese Kabuto to the German Pickelhaube. These helmets influenced the designs of various other helmets across medias. A villain in a Cool Helmet might be a nerd underneath. A Sub-Trope of Nice Hat. A Sister Trope to Cool Crown. Compare Collapsible Helmet. Contrast Helmets Are Hardly Heroic. Examples of Cool Helmet include: