I feel like a long time ago i saw something like that in the shallows of a lake.
I am no expert but perhaps it is some kind of very large tubifex worm which is normally aquatic so it would be strange unless there is some body of
water or perhaps a septic tank leech field...
Personally if I saw this I would somewhat feel like killing it, in fear it was a parasite.
I used to have a dog who was afraid of worms, it would bark at them, then roll over on top of them and literally flatten them to death.
Sides, a surfaced earthworm is an eaten earthworm round here.