The magician removes a large card from an envelope. The envelope is shown empty. The large card is turned around to show a picture of an animal (lets say a dog) the card is placed back inside the envelope and it is left on display, the card is clearly visible through a large window in the envelope. Next, a helper is enlisted to choose an animal from a pack of animal snap cards. All the cards are shown to contain a random mixture of animal images. The helper chooses an animal card and keeps it to themselves. The magician triumphantly states that the animal will match the one inside the envelope. Oops, the selected animal is NOT a dog it is (lets say a rabbit) Time for a little magic, the magician removes the card from the envelope and the card has transformed into the image of a rabbit!