Zac Efron fans have claimed the actor looks unrecognizable in a new video.
The 17 Again star, 33, participated in Bill Nye's Earth Day! The Musical, which premiered on Facebook Watch on April 22.
Although the US star made a very brief appearance in the footage, his new look caught the attention of many.
Fans subsequently took to social media to comment on how different Efron looks.
"I refuse to believe this is Zac Efron," one wrote
Many others then went on to compare him to a number of famous fictional characters.
One Twitter user thought that Efron looked like Shrek's human incarnation in the music video.
They questioned: "is Zac Efron planning to be casted as Shrek in a live action [sic]."
A second suggested that Efron appears like another well-known animated face.
They wrote: "Holy sh*t I can't believe Zac Efron is Handsome Squidward."
But the comparisons didn't stop there.
A third Twitter user wrote: "Zac Efron really be looking like Thanos and it's a crime."
However, while many people thought that the 33-year-old looked unrecognizable in the music video, there were some people who couldn't see the difference.
One Twitter user wrote: "am I the only one that still thinks zac efron looks the same? [sic]"
A second added: "zac efron is not going to look 18 forever ya'll are weird [sic]"
Meanwhile, a third wrote: "Zac Efron is hella cute in this picture idk what y'all say. He doesn't even look that different either, just filled out in the face a little (cause, y'know. Humans do that?). [sic]"
Efron wasn't the only star to feature in the Earth Day video, and it also featured cameos from Gaten Matarazzo of 'Stranger Things', Broadway star Idina Menzel, DJ Steve Aoki, and Dixie and Charli D'Amelio of TikTok.
Watch the video below:It was created to draw attention to the work of young activists like Greta Thunberg who are working tirelessly to save the planet.
The video takes a behind-the-scenes look at the fictional Broadway musical which is starring Justin Beiber as Bill Nye as he tries to inspire other young people into taking action to tackle climate change.