Wizards are popping up on pumpkin stems now too. This is the wizard’s magic. That is why the pumpkin is so sweet.
This is your answer to the association that pumpkins have with Halloween. The wizards have a deep connection with them and their magic is the reason that these pumpkins are so sweet. One concern can be that this pumpkin is actually a wizard who has been magically converted into a pumpkin but another wizard during a duel.
In such a case, whoever eats this pumpkin will be responsible for the killing of one great wizard or one great pumpkin perhaps.