The singer is almost unrecognisable in the trailer for the ‘Best Song Ever’ video with his new hairdo, big glasses and geek-chic attire.
Tweeting a link to the trailer yesterday, Harry wrote: ‘You can preorder 'Best Song Ever' now!!! Marcel would really appreciate it.’
1D fans were also treated to a glimpse of band-member Liam Payne wearing a retro tennis-inspired ensemble complete with a blonde wig and fluorescent headband.
The singer joked about his new look on his Twitter account, writing: ‘gutted I left that headband on settttt.’
The teaser trailer reveals that Liam’s alter-ego in the song video is a camp choreographer called ‘Leeroy.’
Zayn Malik’s transformation is the latest to be unveiled as he embraces his feminine side for the boyband’s new video.
The singer can be seen sitting in his dressing room as a number of hands cake him in make-up and fake tan in the latest teaser trailer.
But it’s probably Irish band-member Niall Horan who has the most extraordinary transformation, donning rubber prosthetics to look like Apprentice star and business tycoon Alan Sugar.
The images of Niall in his Sugar-style costume emerged earlier this week, while Louis Tomlinson’s video alter-ego is yet to be released.
The photos come as their track ‘Best Song Ever’ was leaked and found its way online on Wednesday.
The full video, which will see all five band-members transformed as different characters, is expected to be released on Monday.