Saw this thing a couple weeks ago. After spending hours researching I can only deduce it is a leech. I tried baiting it with bloodworms and the glass planaria/leech trap and ammonia bombed the whole shrimp colony. All 90 something died overnight. I thought the leeches were gone too. Replaced the shrimp colony only to see this wriggling boy next to my first shrimp death... actually believe it or not 2 shrimp lived from the bloodworm vial of death. I named the male Rupert, a Survivor dad joke, and didnt name the female. Well that dead shrimp is actually Rupert.. so idk Im out of ideas, afraid of trying to trap leeches again
EDIT:
Chose not to copper bomb the tank. I stabbed it with tweezers dunno if I killed it. Havent seen it