More than 10,000 Santas are preparing to lay siege to Londonderry in a bid to put the maiden city into the Guinness Book of Records.
Seeing Santas ... there'll be thousands of them!
Heavy rain hasn't put people off registering to don their Santa suits and get out there on Derry's walls on early Sunday morning.
"I'm full of hope about making the world record," said one of the organisers Helena Hasson.
"The weather is terrible, but people are still registering.
"In Las Vegas, 7,259 Santas got together recently so that is the figure we have to beat. If all the people who have registered turn up, then there should not be a problem."
Martin Mullan, chief organiser of 10,001 Santas, said he believes that the turn-out for the event, which takes place at Guildhall Square on Sunday morning, will be phenomenal.
"We have promised the people of Derry, a magical day in return for coming out and supporting this world record attempt.
"Everyone wants to see our city break the world record and that's what we'll do if everyone who has registered comes along and makes their registration count!".
The youngest person to register so far is Niamh Casey. At just three months old she has had no problem filling in her sponsorship form.
It has been signed by Taoiseach Bertie Ahern who promised her £5 and when Northern Ireland First Minister Ian Paisley and his Deputy Martin McGuinness saw this at Stormont last week, they each put themselves down for £5.50!
Adults pay £10 to register for the event and children pay £5. But people who cannot make the Santa parade are also donating money to the cause and the 10,001 Santas hope to raise up to £100,000 for charities.
Among the groups who will benefit are Children in Crossfire, the Foyle Hospice, iCare 4Autism and Macmillan Cancer Support.
The police are advising motorists to expect some traffic disruption in the city on Sunday morning.
Those attending the event are urged to get there early, to make use of the city's many car parks, and to follow the directions of the stewards on duty. Everyone is advised to wrap up warm underneath their Santa suits, bring some snacks and be part of the magic.