During the Bubonic Plague, doctors wore these bird-like masks to avoid becoming sick. They would fill the beaks with spices and rose petals, so they wouldn’t have to smell the rotting bodies. 

A theory during the Bubonic Plague was that the plague was caused by evil spirits. To scare the spirits away, the masks were intentionally designed to be creepy. 

(via dragonesdelaemperatriz)