For its Christmas spot this year, Sainsbury's has taken one of the U.K.'s most loved children's book characters, Mog the cat, and created a delightful and heartwarming animation.

Directed by Outsider's James Rouse with animation by Framestore (the VFX house that brought "Paddington" to life earlier this year) and a voiceover by Emma Thompson, the ad sees Mog causing calamity as well as saving the day, just as in the first book by author Judith Kerr, "Mog the Forgetful Cat."

While her human owners are asleep upstairs -- with even their dreams beautifully animated -- Mog notices smoke coming out of the oven, accidentally calls the fire brigade by stepping on the phone, and causes utter chaos in the house as she scrambles around the kitchen in terror. It's a scene straight out of a movie, and one which kids and adults alike are bound to love.

When the firefighters arrive to hose down the cremated turkey, Mog is praised for her bravery -- with Judith Kerr, aged 92, playing a cameo as the old lady who says "She deserves a medal," a line from the original book. The film ends with the neighbors chipping in to help salvage the Thomas' family Christmas, and the Sainsbury's tagline "Christmas is for sharing." Mog, meanwhile, is happy with her boiled egg.

Agency Abbott Mead Vickers BBDO created the ad in partnership with Kerr's publisher Harper Collins, and the campaign will also help raise funds for Save the Children to improve child literacy across the U.K. Kerr has written and illustrated a new Mog book, to be exclusively sold in Sainsbury's to complement the story told in the campaign, and there's also a Mog soft toy. The profits from both will go to Save the Children.

In the battle to "win Christmas" in the U.K., so far, it looks like Mog the cat is the frontrunner, at least according to social media, which has been showering it with more love than the much anticipated John Lewis "Man on the Moon" spot. We'd have to agree.