Here is a model of a stretchy CatDog model from the classic Nickelodeon Cartoon.

Model comes in 3 parts for easier printing and better strength of the spring. After printing carefully stretch the spring to separate all the rings, be careful not to stretch it too far as it might deform or break (I have found it can stretch around 3-4x its length and still return to its original shape) No glue required just insert the printed clips into the slots and it's ready to go.

Model stands 130mm tall and 270mm long.