Elaine wrote:

Mary this might blow your mind but before you go after dear old Dad let me
tell you my story.

Same exact thing happened to me this Spring. There in my new primrose and
foxglove bed appeared this wild thing growing I knew was some kind of squash
family member. I couldn't let it take over my new plants so I transplanted
it to a very fertile spot near a composting log pile. It loves it there by
the way.
Come to find out my neighbor had been giving the local birds pumpkin seeds.
We also have allot of squirrels that travel back and forth raiding our bird
feeders and digging holes everywhere they feel like. Best we could figure it
was planted by one of those pesky squirrels. So before you kill your Dad it
might be from a squirrel or even a bird that dropped it in flight?
BYW there was a long debate on this newsgroup about if mine would turn
orange or become some green stripped mutant a while back and so far there
are several of the green stripped variety. I have a bet going with my
brother so this is just an experiment. I would suggest you move it where it
will have lots of room to spread out! And throw some cow manure around it
and see what you get?
Good luck
Elaine in Ga
Zone 7

We grow green striped pumpkins about every other year. Down here in the
south they're called cushaws, easier for us to grow than the big, old
squash they call pumpkins. Make good pies, good as a side dish, etc.

George