This is Peanut the turtle. When she was a small turtle, she got stuck in a plastic six-pack ring, and couldn’t free herself. Over time, as she grew, her body and shell became deformed, moulding to the shape of the ring.
She was found in 1993 in Missouri and taken to a zoo in St. Louis where the plastic ring was removed. Since Peanut’s shell protected her body, she was able to live with it, though some of her organs don’t function properly. If this had happened to a fleshy animal like an otter, the animal probably would have died from an infection.
What can you do to prevent this from happening? Always cut up your six-pack rings, clean up after yourself at the beach, and don’t litter. If an item has any loops or openings it isn’t difficult for an animal to get into trouble. Small plastic bits and cigarette filters also pose a hazard to wildlife. Animals usually can’t tell the difference between litter and food, so they eat the litter, and choke or fill their bellies full of plastic and starve. [Source]