Reading Structures by J.E.Gordon. The soft cuticle of a pregnant locust is presented as the most elastic material, being 30 times more elastic than rubber. He also notes in the text that it is significantly more rigid in male individuals and virgin locusts. By the way, as I googled, graphene foam is more elastic than this locust cuticle according to some data by 200 times, and according to others, even by 80000 times (see comment). It is not in the table because the book is from 1978, and graphene was obtained only recently.
Hi, I'm Rauf Aliev. 