Halloween Mask is an item in Great Pumpkin Island. This mask must be worn in order to be let into the Peanuts gang's Halloween party that you were invited to.
After you finish the World War II minigame, you will find yourself in a yard with a scarecrow. The scarecrow is wearing the Halloween mask. After you grab the mask, it will be transported into your inventory where you'll use it to get into the Halloween Party.
- It appears to be a mask of some sort of ogre.
- It is one of two items you need to obtain in order to get into the Halloween party at Lucy's house, along with the Party Invitation.