It looks like an eggplant that didn't have time to fully ripen/develop for whatever reason. They are very tender plants (nightshade) that don't like cold temps at all. Even 1 night of below 50f will do them in.

How was this growing, in a pot, in the greenhouse, in the garden? How big was the plant? Is it a shrub or tree? It's hard to tell its size from the pictures. It could be an eggplant (aubergine) as Bathgate says.

to me this looks like a Fig

We'll never know unless Robertjames comes back with more info.

By now, I doubt there is anything left of that plant. I don't think we'll ever know for certain.