After playing War with Snoopy, you'll find a scarecrow wearing a green mask. Jump up to get the mask and then enter the party.
its the mask that you get all you do is just put it on
To find a costume for the party on Poptropica go to super hero island and get a super hero costume then go back to great pumpkin island at night(in the game) and go to the pinkhouse on the right side.
you by it from the store
There is no potato farm on Great Pumpkin Island.
It seems you are mistaken you get the costume and invitation in pumpkin patch island, correct me if im wrong.
During Halloween you can wear a mummy, pumpkin, vampire or witch costume.
Linus is in the pumpkin patch to the right.
you help the boy with the blanket roll the pumpkin to his home
The pumpkin head is one of the 4 games at the party, which occurs after Snoppy's adventure. The "pumpkin head" costume is not on Great Pumpkin Island. It is a costume change that can be triggered (and reversed!) by typing the costumizer command : Ctrl +Shift +P (all at once). This does not work as a costume on the island. You have to find the mask on the scarecrow and wear it.
you run as fast as you can
you throw the football into the tree ,and get through enemy territory.then there is a scarecrow with a mask.there is your costume!
When you reach the cliff, stop the pumpkin. There is a ramp leading down, with a pumpkin flag checkmark.