The unnamed woman left a scornful note in the hope that the mystery might return after finding the pumpkin missing.
The parent wrote: ‘To the person who stole my son’s pumpkin:
Thank you for the life lesson. This will help teach him that sometimes people are mean for no reason and you have to just brush it off.
Because my son is 2-yrs-old and cannot read this sign, I will add: You are an a**hole.’
The sign appears in front of an array of expertly carved pumpkins left on the doorstep, signalling that the mother had had to carve some new pumpkins or that the remaining pumpkins had lost a friend.
The photo was posted on social sharing website Reddit.
In some cheerier pumpkin news, a man, specifically a vegetable artist, has crossed the Solent from Portsmouth to the Isle of Wight in a giant pumpkin.
Dmitri Galitzine made the trip in the hollowed out fruit in just one hour and 56 minutes.
Mr Galitzine, who used a paddle to power the boat, said: "It went really well, I took on quite a bit of water along the way which was a bit alarming but I made it. It was a little bit nerve-wracking, those ferries go quite quickly as it turns out.”
There are in fact International Pumpkin Boat Championships, which are held in Southern Germany.
Dmitri will compile footage from the challenge to collate an artwork named ‘The load of a man is his coracle.’