Black Oni Mask

Origin
Dated around the early 1600s, oni are Japanese devils or ogres, said to be hidden from human sight.

Description
This is the mask of a hideous creature with shaggy black hair, green skin, pustules on its cheeks and two large curved horns coming from its forehead and 2 tusks protruding from its upper lips. However, when one or more people are directly observing it, its appearance changes. It will turn into a normal looking mask or piece of headwear to avoid suspicion.

Effects
Putting the mask on renders you invisible, but transforms you into the monster itself. Luckily, no one sees you. You CAN be seen on security cameras and via infrared cameras though…