Dragon Egg masks are lost artifacts that look like helmets disguised as large eggs. A human can fit their entire head inside, obscuring everything above the shoulders.
The wearer can see glowing silhouettes of any object made of precious metal within 300 paces. Of course, the downside of wearing an egg on one's head is being unable to see anything else. Wearers of Dragon Egg masks must either be lead by a guide or constantly swap the mask for normal headgear when moving.
A secondary effect is that dragons are fooled into thinking the mask's wearer is a dragon egg. Whether they can see the wearer's body or just think the egg is floating in mid air is uncertain, as is why they do not question the sudden appearance of a mobile dragon's egg. Dragons do not attack mask wearers, but female dragons have a 5+ on 1d6 chance of trying to sit on the egg.
There is conflicting lore about how many masks there are. At least one source suggests there is one mask for each kind of dragon, and each mask only protects the wearer from that type of dragon. Others say the different colorations are purely cosmetic and have no such limitation. One contrary opinion is that there is only one mask, and it changes its appearance to match the type of the nearest dragon, protecting only against that type.