Elf on the Shelf is a reasonably new Christmas tradition based on a 2005 children’s book written by Carol Aebersold and her daughter Chanda Bell. 

The story goes that Santa’s “scout elves” hide in people’s homes to watch if families are being well-behaved. 

Once everyone goes to bed, the scout elf flies back to the North Pole to report to Santa the day’s activities, good and bad, to decide whether members of family will be put on the naughty or nice list. 

The scout elf then flies back from the North Pole and hides in a new spot around the house, turning into an ongoing game of hide and seek. 

Over the years, the Elf on the Shelf doll has become available to buy, and parents have been having fun with them as much as children. 

Those looking to purchase a doll can look no further than Amazon, John Lewis or the Elf on the Shelf online store - prices begin from £19.99 and the doll comes with the Elf on the Shelf book. 

Elf on the Shelf comes in a variety of looks and genders on these sites. 

Whether you're new to Elf on the Shelf or you are digging out Santa’s little helper from last year, there is one very important rule to remember - do not touch the elf, for if they are touched they could lose their Christmas magic. 

If the elf is touched you need to apologise and write a letter to Santa to attempt to reverse the damage. 

Many parents participating in the Elf on the Shelf tradition post hilarious photos online of the doll’s arrival. 

Last year, elves were seen bathing in marshmallow jacuzzis, stumbling into the home drunk and stuck in sweet jars. 

This year, elves have been seen riding miniature pigs, partying with Barbies and hiding amongst Christmas decorations.