9 Form the dorsal fin by folding the pointed flap in half, while folding the entire model in half. Use the creases that you installed in Step 8 to make the fin stand vertically above the dolphin’s back. 10 Valley-fold the indicated flaps up on each side of the model. Follow the thicker, folded edge at the back with your creases.
11 Valley-fold the indicated corner of the flap down, making a crease that spans the back corner and the large bottom corner. Unfold. Repeat behind. 12 Make the flaps trim: A) Valleyfold the top edge to the crease formed in Step 11. B) Fold the flap down using the existing crease from Step 11. Repeat behind.