Video report by ITV News Royal Editor Chris Ship
William and Kate arranged for the pupils of Holy Trinity First School in Berwick-upon-Tweed in Northumberland to get a visit from three reindeers - Chaz, Crackers and her six-month-old calf Echols.
The trio munched on hay bales and their favourite treat of Arctic moss while they were penned in under a tent.
Kensington Palace arranged for Rent A Reindeer to take the three animals to the site on Monday as a treat for the school's 175 pupils.
As local group The Earl Grey Saxes played Christmas tunes, including Rudolph The Red Nosed Reindeer, William and Kate chatted to pupils and teachers in the playground.
The royal couple thanked teachers for their efforts to support learning during the pandemic during the second stop of their 1,250-mile train tour designed to express their gratitude to people who kept the country going during lockdown.
Some of the children wore antlers on their heads and some donned Santa hats for the lunchtime visit.
After the visit, headteacher Nicholas Shaw said: “It has been fantastic and the children loved it.
“We feel honoured to have been chosen and appreciate they are taking the time to think about teachers and the work that has been going on in schools.
“It has been a challenge during lockdown, a lot of new skills have been learned.
“We stayed open throughout for children of key workers and vulnerable children.”
Berwick-upon-Tweed was the second stop for the royal couple after arriving in Edinburgh earlier on Monday.
William and Kate’s third stop was Batley Community Centre in West Yorkshire where they met volunteers from a centre who have supported elderly members of the community throughout the pandemic.
The volunteers sent cards, had regular phone calls and dropped off shopping, food bags and activity packs throughout lockdown.
William and Kate also met Len Gardner, a local resident with whom the duchess has been chatting on the phone after she secretly volunteered through the NHS Volunteer Responder Check In And Chat scheme.
The duchess and Mr Gardner exchanged Christmas presents outside his home.
However, it wasn't the first present Mr Gardner received from the duchess. He said that after talking to Kate on the phone about his love of Italian food he received a pasta making machine from Buckingham Palace.
Reflecting on the phone call, Mr Gardner said: "The first question I had to ask (the duchess) 'how should I address you?' because I like to do things properly.
"She said 'call me Catherine' and from that moment on for the next 30 minutes it was Catherine and Len."
He added: "We talked about what I'd done in work, we talked about children and what they do, she also talked about her children.
"It was all the ordinary things in life - a very nice conversation."
The royal couple intend to stop at 10 destinations during the three-day tour on the royal train and meet key workers including care home staff and volunteers to learn about the challenges they faced and their inspiring stories.
They set off on the royal train from Euston station late on Saturday.
Before setting off, Kate wrote a thank you message to public transport workers on a London Underground white board at the station.
She wrote: “Thank you to all transport workers everywhere for keeping the country moving throughout this difficult year. Wishing you all a very Merry Christmas! Catherine, William”
The tour, which ends on Tuesday, will make stops in England, Scotland and Wales with many of the destinations en route being kept secret.
It is thought the tour will be the duchess’s first official journey by the royal train despite having been a member of the monarchy for almost a decade.
The train, called the Royal Sovereign, has been in its current formation of carriages since 1977.
It features private carriages for both The Queen and the Prince of Wales, with the head of state’s featuring a bedroom with a single bed, sitting room, desk for working on the go, dining quarters – and a bathroom complete with a full-sized bath.