According to Google Lens it's a Great Diving Beetle larva. Cannot verify.
EDIT - tried again, and this time it says it's a Rove Beetle. So I wouldn't put toouch faith in either result tbh.
Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.
According to Google Lens it's a Great Diving Beetle larva. Cannot verify.
EDIT - tried again, and this time it says it's a Rove Beetle. So I wouldn't put toouch faith in either result tbh.
Black Clock Beetle I think, some info: https://www.ukbeetles.co.uk/pterostichus-madidus
I read the second word of your comment very wrong
Bit blurry but either a type of rover beetle or a beetle larva.
It seemed like a larva, it was pretty translucent. The question is: what kind of beetle?