A Purple Cow consists, basically, of purple grape juice and milk and/or milk products.   There are more variations than breeds of real cows.  Kids love it, partly because it turns their tongue purple and gives them a violet mustache.  They can also recite the poem while drinking it.   There's few beverages that pack more nutrition.  Here's several versions; take your choice.

Purple Cow # 1
From The Sneaky Kitchen

1 1/2 cups cold skim or reduced fat milk
3 Tablespoons frozen grape juice concentrate
1/2 cup low-fat vanilla frozen yogurt or ice milk
5 medium ice cubes or the same amount of crushed ice

Place all ingredients in a blender and process until smooth.  Enjoy!

Purple Cow # 2
from Iowa Farmer Today Online

3/4 C. 1 percent low-fat milk
1 1/2 T. frozen grape juice concentrate
1/4 C. fat-free vanilla yogurt

Combine ingredients in a container with lid and shake until well blended. Pour into a tall glass.

Nutrition facts per serving: 180 calories, 2g fat, 30 percent daily value calcium.

Welch's Purple Cow
from Welch's "Cooking with Kids"

Welch's Purple Grape Juice
Vanilla ice cream

In a 12 oz. glass, combine two scoops of vanilla ice cream with chilled Welch's Purple Grape Juice.

Frozen Purple Cow
1 cup milk
3/4 cup grape juice
1/4 cup sugar
1/3 cup lemon juice

Whisk together milk, grape juice and sugar. Add lemon juice. Pour into molds and freeze.