Zach Braff and Dax Shepard's 'deeply disturbing' face swap photo goes viral

Zach Braff and Dax Shepard have always been a popular celebrity-doppelgänger duo (REUTERS)

The Internet had to do a double take after Zach Braff posted a face swap photo of himself and his pal, Dax Shephard, on Twitter Wednesday.

The "Scrubs" star said Shepard's wife, Kristen Bell, took the picture "years ago," and he just had to share with his fans. Braff's tweet went viral, garnering more than 5,400 retweets and nearly 40,000 likes as of Thursday morning.

"I'm gonna get this put on a T-shirt," Braff joked.

Hundreds of people replied to the photo, which they called a "brain twist." And Shepard was quick to add his hilarious commentary to the mix.

"Am I the only one that finds this deeply disturbing but can't stop looking at it?" one Twitter user asked.

"Nope." Shepard replied.

"Am I the only one that finds this deeply disturbing but can't stop looking at it?"

— Twitter user @AprilDelRario

Shepard added, "For me, it's really the pictures in the left column. I mean, it almost appears that there was no swap there."

"I’m frightened and fascinated!" another wrote, soliciting a smiley face-filled reply from Shepard.

"I am gonna be honest 4 several years i thought you were the same person..." another fan admitted.

Braff and Shepard have always been a popular celebrity-doppelgänger duo. Two days prior, Braff posted another picture of the pair high-fiving with the caption, "It's like looking in a mirror."

So it's no surprise fans occasionally get confused.

"Had a dream that both @IMKristenBell and @zachbraff lived in Australia and were my best friends and then utter devastation when I woke up," one Twitter user wrote in January, mistaking Braff for Shepard.

Braff went along with it, responding, "We do live together. But in LA and she calls me Dax for fun."

"When you tweet me it's like I'm tweeting myself in the mirror. #inception," Braff tweeted Shepard in August 2014.

Shepard and Braff are embracing their "bromance." The "Parenthood" star recently invited Braff to guest star on his "Armchair Expert" podcast, dubbing it the "doppelgänger episode" with his "long lost separated at birth twin."

The podcast, which Shepard began hosting in February, has already aired 11 episodes with celebrity guests including Bell, Anna Faris, Ashton Kutcher and others.