There are some pretty odd local customs around, but the Burning of Bartle in West Witton (Yorkshire) probably takes some beating.
I will paste below the several theories of the history of the tradition, but let me first describe what actually happens:
On a cool and misty late summer night after heavy rains, a Northumberland piper dressed up as some sort of "green man" begins playing a haunting pagan tune while standing in the shadows of trees on a hillock in West Witton, as nearby a man from Highways places "Road Closed" signs up and redirects traffic.
Slowly, a small crowd accumulates.
The crowd continues to accumulate, as nearby people come out of their houses.
Then, from down the hill, come a couple of men carrying a figure made of straw, wearing a rubber Halloween mask with eyes that light up. Bartle.
West Witton village is about a mile long. Men (not necessarily the same men) carry this figure the length of West Witton, getting waylaid at numerous places by people standing outside houses and pubs and the village shop carrying a tray of drinks. John, the "master of ceremony" as it were, holds a heavy stick against Bartle's chest, chants a pagan-sounding litany, which ends with everybody shouting "hip-hip-hooray". And the men drink. The piper accompanies.
This is why it is not necessarily the same men who do the carrying through the whole village, as after a few stops to down double shots of whiskey and a beer, they get a bit unsteady on their feet.
By the end of the village, that small crowd has somehow organically accumulated into a very large crowd, and it fills the village street like a crowd streaming out of a football ground. At this point, Bartle is burned. Songs are sung. Then people go and get drunk(er) in the pub.
So here are the possible histories of the tradition, from the official website:
Bartle as a statue (16th Century)
'Bartle' is a common name for 'Bartholomew' and there are obvious links here in that the ritual takes place near St. Bartholomew's day and the church in West Witton is dedicated to St. Bartholomew.
One version of the tale is that 'Bartle' was a (wooden) statue of St. Bartholomew that the villagers attempted to hide from the ransacking of the Reformation in the 16th Century, taking it from place to place until finally 'losing' it at Grassgill.
Bartle as a sheep thief (unknown)
One of the most popular origins is that Bartle was a sheep thief who was chased around the village when they took the law into their own hands. Although one of the most popular tales in the village, this version does miss any obvious connection to St. Bartholomew
Bartle as a holy man (16th Century)
Another idea from the 1500s is that Bartle was, in fact, Abbot Adam Sedburgh of Jervaulx Abbey. Jervaulx is close to West Witton (approx. 9 miles) and there are links between the Abbey and buildings here. Abbot Sedburgh was apparently trying to dodge the draft for the Pilgrimage of Grace, a mass march to London protesting against the Protestant Reformation. Unfortunately, records exist that show that the Abbot was actually hanged at Tyburn, York, so this casts some doubt on this theory.
Bartle as a pig farming giant
A truly 'mythical' version of the story has Bartle as a giant, the son of Norse god Thor. When one day the giant, who for unknown reasons had taken up pig-farming near Witton, discovered his prize boar missing he blamed the folk of West Witton. Being hardy folk they weren't perturbed and eventually chased and killed the giant, setting his 'castle' ablaze in the process.
What seems most likely is that the modern tradition of Burning Bartle is an amalgam of many old (and ancient) customs and traditions, possibly stretching back to pagan harvest rituals (as many August/September rituals do). Over many hundreds of years the ritual has been modified and altered to suit the age and the news of the time, resulting eventually in what we see today.