This is a mutant marbled crayfish. Unlike other crayfish and most everything else, it reproduces all by its lonesome. And like other female crayfish they produce eggs in the thousands. These mutants are a little bigger and have been pretty good invading other crayfishes' territories. The whole story is here:
https://mobile.nytimes.com/2018/02/05/science/mutant-crayfish-clones-europe.html?smid=tw-nytimes&smtyp=cur&referer=https%3A%2F%2Ft.co%2FMjGULmW8ll%3Famp%3D1