There's a BBC video of it here and some photos. 10" long apparently and black bellied. It's been designated endangered in Alsace in France and a program of breeding and crop growing going on there to try and save it from becoming extinct. In Germany they have programmes as well I think.
https://www.bbc.co.uk/programmes/p07vfb4b
https://www.boredpanda.com/wild-euro...mpaign=organic