It almost looks like an old railroad spike
Telephone pole step spike. Was used to clime poles years back.
Not any railroad spike I've ever seen
https://www.google.com/search?clien......1c.1.64.psy-ab..0.14.1468....0.vfPVz6EOIhg
Got Pics of the Whole thing ? & Measure it
I didn't look real close but no I don't think any of mine
popped up with that search term