Grease and flour a bundt pan. In a large bowl, combine dry cake mix, cubed watermelon, gelatin powder, egg whites and oil. Beat until smooth. Pour into a prepared pan and bake at 350 degrees for about 35 minutes or until cake tester inserted in cake comes out clean. Cool on a rack and frost with watermelon icing.

Icing: Beat cream cheese and butter until fluffy. Add sugar and watermelon juice; stir until blended.