He plays an elf called The Wolf, one of Santa’s two elf helpers (Dan Starkey plays the other, Ian). Santa and his elves hook up with The Doctor and Clara Oswald when Santa’s sleigh crashes into Clara’s snowy roof.
“There’s less swearing and it’s less crude than Misfits,” laughs Nathan (left). “Santa and his elves are a team and look out for each other. But you can tell they spend a lot of time together – they’ve done a lot of journeys to a lot of houses! But they become unlikely heroes.
“This adventure sees Santa visiting a sci-fi polar base, then trying to save the day because he’s called upon. It’s not, ‘Who Ya Gonna call, The Ghostbusters?’ On Christmas day it’s got to be Santa…”
Nathan says he particularly enjoyed The Wolf’s elf costume and pointy ears, especially wearing the huge elf-like shoes.
“When I went to the costume fitting I was half expecting a bit of green Lycra and some sort of a tacky costume – but it’s one of the best costume fittings I’ve been to. Usually it’s jeans and trainers for me, or a Misfits orange jump suit, but this time it’s a character that has its own identity. As soon as you put it on, you are the elf.
“I’m hoping to take the elf shoes home with me! They engulfed my foot and were extremely comfortable. When I was filming I FaceTimed my daughter, Sadie, who’s nearly two, and the first thing she said was ‘Shoes!'”
Working with comedian and film star Nick Frost, who plays Santa, was like a dream come true for Nathan.
“I was a little star-struck to be honest and that’s the first time that’s happened to me with anyone I’ve worked with. I grew up watching Spaced, Shaun of the Dead, and Hot Fuzz, and at the read-through, when he walked in the room it was like I had tunnel vision. I had to calm down and realise, I’m not a fan now, I’m a work colleague.
“Nick’s probably the most iconic Santa I can think of. Obviously there are a lot of Santa films, but he brings that little bit of comedy and something different that I think will be the one that you remember most.”
Although there’s a ho-ho-ho-ing Santa, there are plenty of scary monsters called Dream Crabs and Sleepers in this Doctor Who Christmas special, although it won’t stop Nathan sitting down on Christmas Day to watch with Sadie.
“I will sit with her and be there to shield her eyes when she starts getting scared… I guess with kids when it’s something a little bit scary they almost get drawn to it, don’t they? I’ll see if she recognises me or does that double-take thing: ‘How are you there at the same time?’ I think she will find it a little bit too scary so I’ll go off and see if there’s any chocolate to distract her!”
Doctor Who: Last Christmas is on BBC1 this Christmas Day at 6.15pm