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.
There is no pigeon on great pumpkin island.
The pumpkin patch is to the right on Great Pumpkin Island. It was the only area shown in the island preview.
The pumpkin head is in Time Tangled Island and you have to find it.
There are no buildings or upper rooms on Great Pumpkin Island.
The name of the island is Great Pumpkin Island. See the related question below.
you wait for the great pumpkin!
At the very end, there is a mysterious figure in the pumpkin patch!
You are drawing on his head -- the pumpkin gets carved the same way. Whatever face you draw will work.
There is no potato farm on Great Pumpkin Island.
No. And that is not how to get a costume for the Island's purposes. Ctrl + Shift + P toggles the "pumpkin head" jack o'lantern on the Costumizer. On Great Pumpkin Island, you have to get the costume that is provided on the island. At the end of Snoopy's Flying Ace adventure (dodging the searchlights) you arrive at a farmhouse. There is a mask on the scarecrow there. Get it and wear it when you knock on the door.
Great Pumpkin Island
That is not a feature of the island. You can get a costume change using the costumizer by pressing the 3 keyboard keys Ctrl+Shift+P all at the same time. You remove it the same way. You cannot use this or any other costume for the halloween party on Great Pumpkin Island. You have to get the mask from the scarecrow in Snoopy's adventure.