American Greetings Unicorn Party Supplies, 16 Oz. Plastic Party Cup (8 Count) Satin slips Satin_lover71 Flickr. Create some magic at your child's birthday party! These brightly decorated birthday party cups feature unicorns, cupcakes, rainbows and sprinkles in a colorful wraparound design. A sweet and stylish choice for your child's party theme, this reusable, 16 oz. Souvenir cup is dishwasher safe and can double as a party favor, keepsake cup or favor cup. The convenient package of 8 birthday cups is sure to keep all of your guests hydrated as they frolic and play. Coordinate plastic cups with other unicorn themed birthday supplies for party decor that sparkles!