It's one of the most iconic advertising symbols of all time - but then, nothing is sacred in the cola wars.
PepsiCo has taken great delight in recruiting Santa Claus, Coca-Cola's unofficial symbol for more than eight decades, for its latest U.S. advertising campaign.
The commercial stars a short-sleeved Santa who does the unthinkable and deliberately picks Pepsi Cola over Coke - because he's 'on vacation'.
Scroll down for videos
Off-duty: PepsiCo's new advertising campaign stars a short-sleeved Santa who chooses Pepsi over Coke because he's on vacation
Appropriation: Pepsi's summer advert shows a short-sleeved Santa dancing on the beach - and then going to order a Pepsi, not a Coke, from the bemused bartender
Santa has been an intrinsic part of the Coke brand since 1931, and the company is credited with forever fixing his image as a fat, jolly man in the red and white suit
Although Pepsi's appropriation is nothing new - it recently emerged ginger ale White Rock used a red-and-white Santa in its advertising as far back as 1925 - It's a sure sign the legendary cola wars between the two rivals are back.
PepsiCo is desperately trying to increase sales after Diet Coke leapfrogged its regular brand to become America's second most-popular soda for the first time ever earlier this year.
The battle has begun with Summer Time is Pepsi Time, the company's first advertising campaign for its regular brand of cola in three years, which aired this week on ABC.
The original: Haddon Sundblom's first ever Coca-Cola Santa Claus made his debut in 1931
It features Santa Claus - dressed in a red Hawaiian shirt - dancing on the beach.
When he gets thirsty he heads over to a cabana to find the bartender is already holding two bottles of Coca-Cola.
Santa shakes his head and says 'make it a Pepsi'. The confused bartender replies: 'But Mr Claus, I thought you had a deal with - you know.'
Then Santa leans in and says: 'I'm on vacation. Gonna have a little fun!'
Enduring icon: Mr Sundblom's 1936 design shows Santa playing with the toys he's delivered
Post-war Santa: This 1956 advert shows a hatless Santa with a full red coat rather than his old overalls
Legendary image: This 1964 advert shows Santa playing with two children and their newest gift, a puppy. Artist Haddon Sundblom first used a friend to model as Santa, but after he died he used his own face as inspiration
Pepsi-Co has a long history of rattling Coca-Cola with cheeky advertising campaigns, most notably with its taste challenges in the 1980s, which even pushed its rival into the disastrous move of replacing traditional Coke with New Coke.
But with its latest advert, PepsiCo takes a swipe right at the heart of the Coca-Cola brand.
The firm first started using Santa Claus as a symbol in 1931, when Swedish-American artist Haddon Sundblom was commissioned to create the first of 40 oil paintings.
Inspiration: After the death of the friend he used as a model for Santa, Haddon Sundblom used his own face for the paintings
Man behind the image: Artist Haddon Sundblom, left, is credited with forever fixing the red-and-white image of Santa Claus in the public imagination but, right, he had already been used in a 1925 White Rock advert
He modelled Santa on his friend, retired salesman Lou Prentiss, and after he died, he used his own face for inspiration.
Before Mr Sundblom, St Nicholas had been variously depicted as thin, in a green coat, or even as a ghoul, and his image as a jolly man in a red and white suit only became fixed with that first advertising campaign.
After his death, images based on his paintings continued to be used in television campaigns, magazine adverts and billboards.
Modern incarnation: Last year's Coca-Cola Christmas commercial showed Santa using a snow globe to cheer up the planet
PepsiCo's chief executive officer, Massimo d'Amore, told the Atlanta Journal-Constitution: 'Pepsi has a tradition over time of doing this kind of communication.
'It's funny and witty. Everybody benefits. The category grows, and it's something U.S. consumers love to watch. It's a competitive spirit.'
PepsiCo has increased its spending on U.S. television advertising by 30 per cent this year, and has sponsored the American version of The X Factor for $60millon.
Summer Time is Pepsi Time advert