1. Take your banana and make a cut with a knife into one end to form a dolphin's "beak".
2. Draw an "eye" onto the outside of the banana's skin close to the mouth, using a marking pen or biro. You could add "fins" on either side of the body, if you wish to make it even more realistic.
3. Carefully place a whole grape into the dolphin's mouth to make it look like he is playing with a ball. You could make a whole family of dolphins for a water themed birthday party or perhaps just for fun. Enjoy.