History of Halloween Pumpkin
The story of Halloween pumpkin was told very long time ago. The original vegetable used is turnip. It was used by a poor soul named Jack.
He couldn't go to both Hell and Heaven because he's not good enough to go to heaven and he had a commitment with devil not to send him to Hell.
He needs some eternal flame to light him forever. Therefore, he used turnip with the candle light inside and carry along everywhere (sound so scary!!)
However, when this culture comes to the US. Turnip was changed to pumpkin because it's just more convenient.