We're all in this together… Zac Efron is set to play the infamous Ted Bundy in an upcoming biopic — and the High School Musical star gave fans their first look at his transformation into the serial killer. Wearing his signature white tee, Zac's resemblance to the criminal is seriously creepy. But, that's not the only thing that's creepy. A source exclusively told In Touch that Zac's personality actually changed during filming.

"He got really lost in his portrayal of Ted," the source revealed, "so much so that he acted like a real jerk and a creep to the cast and crew, and even to some fans in town. Many people on set didn't think it was an act, and he had to apologize. And now there are some fans out there who think Zac's really rude!"

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Meet Ted. #behindthescenes 🎬

A post shared by Zac Efron (@zacefron) on

Yikes! Zac captioned the black-and-white shot, which seemingly shows him recreating his mugshot, "Meet Ted." The 30-year-old will be playing Ted in Extremely Wicked, Shockingly Evil and Vile — which chronicles Ted's crimes from the viewpoint of his longtime girlfriend Elizabeth Kloepfer, according to IMDB.

As expected, fans were shook by the transformation but at the same time excited about his portrayal. "I’m excited to see him as a serious character again," one follower commented. Another added, "This is the best thing I’ve seen all year." Previously, Zac opened up about the role and admitted it was not going to be easy getting into the mind of a sociopath. "Ted Bundy is going to be a challenge," he told Teen Vogue. "I think it's going to be different and it's going to be fun. I'm super stoked."

The film's producer Michael Costigan also predicted this would be Zac's best role to date. "[Zac is] perfect casting, as he can play both the depth and the charm that this guy had in equal measures," he said, "and which allowed him to manipulate these women in such a terrifying way."

ted bundy getty

How did Ted Bundy die?

For those who need a Bundy refresher, Ted (born Theodore Cowell) was a serial killer who admitted to murdering over 30 female victims across seven states in the '70s. Described as handsome and charismatic by his victims, he would usually feign injury or disability to gain their trust. He was also known to perform sexual acts on his victims' corpses and kept severed heads in his apartment as mementos — he's not one of the most infamous serial killers for nothing. He was captured for the final time in 1978 in Florida (yes, he was previously arrested for murder in 1975 but managed to escape), where he was executed in the electric chair a year later at the age of 42. We're never going to be able to look at Zac the same way again.