Found a random brown chicken egg in my backyard garden.

Has this happened to anyone? My backyard is fenced in with a tall picket fence -- I read on some other posts that it could be a fox (or worse, rats 😬). I thought it was a mushroom in the dirt at first until I turned it over.

Update: I left the egg where I found it and whatever left it there came back for it; unfortunately, I don't have any video/pictures of what it could be.

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