Nicholas Rogers, a historian at York University says that when people prayed for the dead at Hallow Mass, they dressed up. When praying for fertile marriages, the boy choristers in the churches dressed up as virgins. So there was a certain degree of cross dressing in the actual ceremony of All Hallows Eve
Not only will these costumes guarantee that you wont run into one (or five) of your twins at a party — you are likely to get way more likes on your Instagram for your creativity as well.
The carving of pumpkins originates from the Samhain festival, when Gaels would carve turnips to ward off spirits and stop fairies from settling in houses.