AceShowbiz -

When Karen Gillan unveiled her bald head at the "Guardians of the Galaxy" Comic-Con panel, she seemed cool with that as she kept on flashing her smile the entire time. Her daring decision to shave her red locks apparently is devastating news for all her fans. The film's director James Gunn reveals he's been hit with hate mail for it.

"If you are sending me hate messages about making @KarenGillan2 shave her head, you might consider the overall state of your life," Gunn tweeted. In the movie, due out August 2014, the "Doctor Who" actress takes on the role of Nebula, an evil space pirate and mercenary who claims that Thanos is her grandfather.

Gunn says that Gillan has been made aware of things she needed to do in order to be the said character. "It was explained that whoever played Nebula would have to shave her head," he explained on Formspring. "So Karen knew about this when she auditioned. A bald cap looks fake when seen repeatedly up close & during long action sequences."

The Comic-Con attendees were not the first to witness. Matt Smith, Gillan's co-star on "Doctor Who", admitted he had known about his friend's new look prior to the Comic-Con revelation. "I knew about [it] actually, because I had dinner with her and [I] was taking her wig off mid-meal," he told Radio Times.

"Weird. Unnerving. And she's unnerving anyway," he commented, as cited by Vulture. "But she's a beautiful girl and she has those blue eyes, she can pull it off."