That's a volunteer pumpkin growing up IN on of the plum trees. Well, growing in, below, and all around....seriously, the vine that pumpkin is hanging from is up in one bed, goes along the plum branches, and is now up in the tree in the adjacent bed!
And the vines are so lush that you can't see the base of the tree, nor the strawberries growing underneath. (Note - all this shade MIGHT not make for the best strawberry harvest next year - we'll see...)
Of the intentionally planted pumpkins, so far I've only seen the ONE forming (pic below), which is smaller than the pumpkin hanging from the tree (pic above). And you can see these are two very different varieties. I think I'm going to need to rig up some sort of support for the hanging pumpkin so it doesn't get too heavy and break it's own vine (or a plum branch!).