The Irish are the reason we have the Jack-o-Lantern (or Jack O’Lantern depending on who you are). Let me tell you a story.
Stingy Jack was a horrid, miserable, old drunk who liked to play tricks on everyone (including his own mother). One day, he had the bad fortune of running into the Devil in a pub and inviting him to have a drink with him. Well, true to his name, Stingy Jack didn’t want to pay a single penny for those drinks and true to his character, he managed to talk the Devil into turning himself into a coin so that Jack could buy their drinks. Rather than buying the drinks though, he stuck the coin into his pocket next to a silver cross (which kept the devil from changing back into his original form).
Eventually, Jack got sick of having the Devil in his pocket and he freed the Devil on the condition that he was left alone for a year and that, if Jack died, the Devil would not claim his soul. The Devil agreed and off he went.
Eventually, the Devil comes back, because really, I mean, who wouldn’t want to seek revenge after being a coin in a guy’s pocket? Jack, as he was wont to do, managed to trick the Devil again. This time, he got the Devil to climb into a tree, supposedly to pick a piece of fruit. As soon as the Devil was up in that tree, Jack carved a cross into the tree’s back and the Devil could not get down. The Devil eventually convinced Jack to let him down, but he had to make the same deal as before, only this time, he couldn’t bother Jack for ten years.
Soon after, Jack died. According to the legend, God didn’t want to allow such a tricky, unsavory sort of guy into Heaven and the Devil was still too angry to want him in Hell. Instead, the Devil sent him away with only a burning piece of coal/candle to light his way through the dark night. Jack came along a turnip, carved it out, and stuck the coal/candle inside so it wouldn’t burn out. Supposedly, he’s been roaming the earth ever since. The Irish dubbed him Jack of the Lantern and eventually Jack O-Lantern. In Ireland and Scotland, people used to make them out of potatoes or turnips. When they came over here, the lanterns went pumpkin. The reason we carve scary faces into them and leave them by doors and windows? To scare away Jack, of course.