Eagle-eyed fans spotted Glee actor Matthew Morrison, 41, during tonight's episode of X Factor : Celebrity.
The Glee star attended the second live show of X Factor's new spin-off to support his friend and former Glee co-star Kevin McHale, who is a celebrity contestant on the singing competition.
Viewers were shocked by Matthew's 'new look' as they noticed him backstage, cheering on his former colleague.
Viewers instantly fled to Twitter to comment on the star's contrastingly different look from his Glee character Will Schuester.
One joked: "Enjoying that Matthew Morrison has kept his porn tache from AHS1984 for the X Factor Celebrity backstage."
While another hilariously questioned: "What is that atrocity on Matthew Morrison’s face?"
One user seemed particularly shocked by the actor's appearance as they tweeted: "MATTHEW MORRISON IS THERE."
Meanwhile, other X Factor Celebrity viewers struggled to look past the TV star's striking moustache and different look from his famous Glee character.
An avid Glee fan posted: "Mr Schuester" followed by a shocked face emoji.
One viewer mocked his appearance saying: "Mr Schue that moustache", followed by a GIF of Nicki Minaj saying 'hell no'.
Another pleaded: "Mr. Schue, shave off that stupid moustache."
While another addressed Matthew's appearance more subtlety, writing: "Wow Mr Schuester’s moustache is erm...interesting..."
The star's look was a stark contrast to his clean-cut Glee character, but similar to his appearance on TV series American Horror Story 1984.
The TV star plays Trevor Kirchner, the activities director at the summercamp Camp Redwood, in the hit horror anthology television series.
The Broadway star supported Kevin who played disabled student Artie Abrams in Glee.
His casting sparked controversy after a group of disabled actors voiced their upset that a non-disabled actor had been cast as Artie.
Kevin told fans in 2009 that he could really walk, which left them surprised at his confession.
But he told PopEater that he's not surprised fans are shocked he can walk because as he says, "I'm really good at not moving my legs."
X Factor: Celebrity continues Saturday at 8.30pm on ITV.
