Aliens?

We have a rather large fern near the entrance door.  I had cut away all of the dying fronds in October which left the cut ends poking above the ground. Not very bonny.

However, the Fern is still in business and is now sending new fronds out. They will gradually uncoil themselves over the next two or three weeks to become the monster it invariably is.

The thing is I never planted it. Another volunteer, and most welcome.