What is frog mouth helmet?

A frog mouth helmet is a type of helmet that has a visor shaped like a frog's mouth. It was typically worn by knights and soldiers during the 14th and 15th centuries in Europe. The visor of the helmet could be opened and closed to protect the wearer's face and eyes during battle. The frog mouth helmet provided good visibility and ventilation, making it a popular choice for combat. Its distinctive design gave the wearer an intimidating and fierce appearance on the battlefield. Today, frog mouth helmets are rare and are mostly found in museums or private collections.