Nelly, the hippo, lives in a big pond in the middle of Africa together with the little turtles and a white heron. She has everything she needs -- water, plenty of food and her friends who comfortably sit on her back enjoying the sun. But some cheeky crabs annoy her because they keep pinching her nose.

Which turtle is able to stay on Nelly's back when she ducks underwater to get rid of the crabs?