Roly-poly, scientifically
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
isopod
(Other definitions for isopod that I've seen before include "Slater, for instance" , "This crusty creature" , "Crawler" , "Woodlouse, say" , "Crustacean with seven pairs of legs for crawling" .)