The Mask of Dr. cons plague in 1500 and has spread to many countries. It was used by doctors to filter the air miasma filled during periods of plague, very common at the time. The doctor was holding a stick for not touching his hands and the plague was protected with a waterproof coat surrounding the mask. The air could circulate only through two notches along the "beak" and was filtered through herbs that were strung on the inside and packed. For these doctors, who were unaware of the existence of germs, the disease was actually caused by spirits, so it's to scare away the costume that they had that terrifying.
