Michael J Fox goes back to Back To The Future for Lil Nas X video

Actor Michael J Fox has reprised his role as Marty McFly in a new video for rap star Lil Nas X.

Fox appears in a trailer for the upcoming single, Holiday, which sees Nas arrive in the Wild West just as Santa Claus is thrown out of a saloon.

After he picks up Santa's hat, Nas discovers he's been chosen as "the new Santa" and must travel to the future.

As he sets off on a reindeer, Fox shouts after him: "Whatever you do Nas, don't go to 2020!"

It is the first time Fox has played his most famous character on screen since an appearance on Jimmy Kimmel's US chat show in 2015.

In the video, he even wears his old cowboy outfit from 1990's Back To The Future Part III, where his time-travelling teenager was trapped in an old Western town.

The cameo comes a week after the 59-year-old said he may be forced to retire from acting.

Speaking to People magazine, Fox said his "short-term memory is shot" as a result of Parkinson's, which he was first diagnosed with in 1991.

"I always had a real proficiency for lines and memorisation," he told the magazine.

"And I had some extreme situations where the last couple of jobs I did were actually really word-heavy parts. I struggled during both of them."

Admitting that "acting is getting tougher to do", he said writing was now his main creative outlet.

Fox was one of the biggest stars of the 1980s, thanks to his roles in the Back To The Future films, as well as the TV sitcom Family Ties and projects like Teen Wolf and Casualties Of War.

He began to notice tremors in his hands while shooting the comedy Doc Hollywood in 1991, and was diagnosed with Parkinson's shortly after.

After going public with his diagnosis in 1998, he continued acting, notably starring in Spin City from 1996-2001 and appearing as a recurring guest star on legal dramas Boston Legal and The Good Wife.

His struggle with the degenerative disease was documented in his 2002 autobiography, Lucky Man, in which he revealed he had turned to drink after the diagnosis, almost destroying his marriage in the process.

He described his symptoms as including "rigidity, shuffling, tremors, lack of balance [and] diminished small motor control". In recent years, he has also struggled with his speech, and practices tongue-twisters to improve his diction.

Lil Nas X, who achieved overnight fame in 2019 with his country-rap crossover Old Town Road, releases his new single on 13 November.

It is not yet known whether Fox will have a bigger role in the full video.

The star last played McFly as a gift to Chris Martin's son Moses, whose favourite film is Back To The Future.

Fox joined Coldplay on stage in New Jersey in 2016, playing Johnny B Goode - recreating one of the original movie's pivotal scenes.

An earlier version of this story incorrectly stated that Fox had not appeared on screen as Marty McFly since 1990. This has now been corrected.

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