When Father Christmas is not at home with the reindeer preparing for his big sleigh-ride, he likes to play practical jokes on the children who visit him asking for presents.
In his grotto in the pine forest at the Wetland Centre in Barnes, southwest London, Santa also has a clear message for anyone who is not sure whether he really exists.
"Part of being a child is believing in magic," says the rotund figure who appears on sightseeing cruise boats on the River Thames too. "Father Christmas is part of that."
. London, United Kingdom. Reuters/Stefan Wermuth
His red and white outfit is custom-made. His beard is the real thing, not to be tugged at by the sceptics.
. London, United Kingdom. Reuters/Stefan Wermuth
More than 2,000 children visit him in these London locations alone. “Talk to them like (you talk) to grownups... Never look down on them,” Father Christmas says.
. London, United Kingdom. Reuters/Stefan Wermuth TPX IMAGES OF THE DAY
He offers a listening ear, and a mischievous wit. When one boy asks for a remote-controlled scorpion, Santa asks whether he might prefer a pink ballet dress instead.
He tells one girl he has wrapped up a tin of cat food for her, before the real presents arrive - a bird book, a toy duck and a candy stick.
The most wished-for gift this year is a hoverboard for boys and a Barbie doll for girls, Father Christmas says.
. London, United Kingdom. Reuters/Stefan Wermuth
John Field, 66, a former teacher turned actor, has taken on the role of Santa for the past 12 years.
“I’m playing a part but it is one of the most truthful parts I can play,” he says.
. London, United Kingdom. Reuters/Stefan Wermuth TPX IMAGES OF THE DAY
“Being a Father Christmas you have to make an agreement, a non-written agreement with both the parent and the child: to believe."
. London, United Kingdom. Reuters/Stefan Wermuth
Amid the excitement as Christmas approaches, Santa is often run off his feet and needs help sorting through all the letters he receives. Britain's Royal Mail, which helps him process the wish-lists, says Lego, bikes and Play-Doh were the top three requests from children who wrote to Santa. Peppa Pig came in at number 10.
. London, United Kingdom. Reuters/Stefan Wermuth
Santa’s job is not without its dangers, but after more than a decade of welcoming children, Santa says it’s rare for anyone to be sick or fail to make it to the bathroom on time.
. London, United Kingdom. Reuters/Stefan Wermuth
The rewards of the job, chief among them thank-you messages, more than outweigh any downsides.
Last year a girl made a poster with photos of her visits over the last seven years. “Father Christmas," she wrote, "thank you for being there every year for me. You make Christmas.”