Source: Into the Nightmare Rift, pg(s). 62
A nightgaunt mask is a blank mask with two eyeholes, which disappear upon being worn. The face of the mask allows the wearer to see normally and protects against gaze and breathing attacks, but does not allow the wearer to speak. After wearing the mask for at least an hour, the wearer can summon a few nightgaunts to serve for a short time, or summon one that serves for 24 hours. The wearer can communicate with summoned nightgaunts via telepathy. The summoned nightgaunts attack the wearer if the mask is removed.