Halloween
The origin:
Halloween originated in Ireland: Since around 700 BC, the Celts celebrated "Samhain" on October 31st, one of their most important festivals. They celebrated their harvest, the start of the cold season, and the beginning of a new calendar year. The Celts also believed that on this day the underworld was open and that encounters between the living and the dead took place.
To ward off evil spirits, people disguised themselves in frightening costumes and haunted the streets at night. Large fires were lit to keep evil spirits away. Small offerings ("treats") were placed in front of houses to appease the spirits and prevent them from committing misdeeds.
The Church referred to the pagan festival in the 9th century as "All Hallows' Eve," the evening before All Saints' Day. The modern word "Halloween" was later derived from this. Since the 19th century, Halloween, brought to America by Irish immigrants, has steadily gained popularity. The most well-known custom involves children dressed in scary costumes going from house to house, saying "trick or treat," demanding sweets or playing tricks on them. Today, the Halloween tradition has spread almost worldwide.

Copyright: gardnerian.de
The pumpkin:
The custom of hollowing out and carving pumpkins also originates from Irish tales. When a wicked man named Jack died, God denied him entry to heaven. But Jack wasn't welcome in hell either. With a piece of coal placed inside a hollowed-out turnip, he set out to find a place where he could stay.
From this legend, people derived the belief that a burning piece of coal inside a turnip had the power to ward off the devil and evil spirits. In the USA, the native pumpkin was larger and easier to carve than turnips. Thus, it replaced the turnip as the Jack O'Lantern – as the carved pumpkin is called in English-speaking countries.

