This strange critter fell out of the mouth of a bluegill after my grandson caught him with a popping bug.

The "tail" looked almost like a round worm from a dog. The "head" was red and appeared to be partly missing.

Any idea on identity? I guess bluegill must like them, or maybe it's some sort of parasite.

The bluegill was the first one he ever caught on a fly rod, and it was quite a thrill for him.