Start with a cup of corn syrup inside a bowl. Stir in a tablespoon of Arrowroot powder or cornstarch. Slowly add in water (up to 1/3 cup) until you get the perfect consistency of blood. This is your base.
To add the dye, add a few drops of red food coloring, stirring it in until you have a bright red color. Add a couple drops of blue or green food color to make the “blood” look more authentic. Set aside to thicken, then apply to face, clothes or body.
Warning: This bogus blood can mark clothing!