YouTube star Mars Argo has told how how her ex-boyfriend punched her in the face and made her life a 'living nightmare' – and stole her identity to create a 'fake' copy of her in the form of YouTube rival 'Poppy'.

In an exclusive interview with DailyMail.com Argo - real name Brittany Sheets – told how Corey Mixter had created Poppy, now one of YouTube's biggest stars, months after she ended their relationship over claims he was cheating on her.

Sheets is suing musician and internet persona Poppy – real name Moriah Pereira - and Mixter, who performs as Titanic Sinclair, claiming their work is simply a copy of the performances which made her one of YouTube's early big names.

Sheets is also seeking a domestic violence restraining order against Mixter who she says repeatedly broke into her apartment and punched her in the face.

DailyMail.com has reached out to Mixter and Pereira and their management for comment but has not receive replies.

YouTube star Mars Argo - real name Brittany Sheets – told DailyMail.com how Corey Mixter had created Poppy, now one of YouTube's biggest stars, months after she ended their relationship.

Sheets claims that soon after she abandoned the persona Mars Argo, Poppy died her hair blonde, started dressing like her and even using a similar voice

Sheets (left) and Mixter (right) first met talking on MySpace in 2008 while they both lived in Saginaw, Michigan and started dating. The following year Mixter began making videos of Sheets and later started a YouTube channel

After Sheets and Mixter broke up, Mixter started working with Moriah Pereira, or Poppy (right), who quickly became a popular YouTube star

Sheets and Mixter first met talking on MySpace in 2008 while they both lived in Saginaw, Michigan and started dating.

The following year Mixter began making videos of Sheets, a competitive equestrian, at horse riding events, then making music in their bedroom and posting videos on their YouTube channel, Grocerybag.tv.

Sheets, who sang in her church choir, starred as her alter ego Mars Argo in the music videos, and Mixter took on the stage name Titanic Sinclair.

'It was a pretty quick period where we went from hanging out to collaborating and being excited about all these music things. And then, romantically involved pretty close to that too,' she said.

Sheets says Mixter seemed like a 'nice guy' at first and they quickly fell in love.

With their channel growing in popularity, the couple moved to Chicago and then in 2012 to Los Angeles, and Sheets began performing at live stage shows.

By the end of 2014, she and Mixter had released 92 videos, a lot of which were shot in a makeshift studio in their apartment, which Sheets says began as a 'really organic, beautiful process'.

Their channel had developed a cult following and was becoming one of the biggest on YouTube.

In clips from YouTube videos, Sheets and Pereira can be seen dressing almost exactly the same. The staging in many videos appears to be similar as well

At the time, Sheets claims, Mixter was relying on constant financial support from her and her family.

Her father, a veterinarian, gave the two young YouTubers a loan in 2013 and set up a company with them, Mars Argo LLC.

But despite her family's support and the couple's online success, Sheets claims she was 'living a nightmare' behind closed doors, suffering 'severe emotional and psychological abuse and manipulation' at the hands of her boyfriend.

Tears welling in her eyes, an emotional Sheets told DailyMail.com: 'Corey made my life a living nightmare, he manipulated and controlled me and made me feel worthless.

'He threatened me and stalked me, monitored me on social media, broke into my home and punched me in the face, I was terrified of him and still am.'

The couple split in 2014 after Sheets confronted Mixter for allegedly cheating on her, and asked him to move out of their LA apartment.

She tried to maintain a professional relationship with him but Mixter began to 'harass, stalk, threaten, and abuse' her, she told DailyMail.com.

Mixter showed up on her doorstep, broke into her apartment building and waited for her in the courtyard, physically assaulted her and threatened to commit suicide in text messages to her, Sheets said in court filings.

With their channel growing in popularity, the couple moved to Chicago and then in 2012 to Los Angeles, and Sheets began performing at live stage shows. Sheets and Mixer are pictured above with musicians Brown Chernobyl (left) and Astro Almost (second right) at an event in 2014

By the end of 2014 Sheets (pictured) and Mixter had released 92 videos, a lot of which were shot in a makeshift studio in their apartment

Sheets gained popularity and even had a circle of celebrity friends, including Game of Thrones star Maisie Williams (left)

According to the lawsuit, Sheets says that Mixter 'calculatedly transformed' his new business partner, Poppy, (together in Los Angeles in 2017) into a 'Mars Argo knockoff'

By mid-2014 she decided to also cut business ties with Mixter and stopped making videos with him.

But Sheets claims that 'Mixter's intimidation only intensified'.

In November 2014, Sheets claims, Mixter broke into her apartment at night through the bedroom window.

'He broke in numerous other times in different ways,' explains Sheets. 'It became terrifying, he would sit in my courtyard and wait for me to get home.

'I lived in constant fear of what he'd do next. The more I pulled away the more aggressive and obsessive he became.'

According to the lawsuit, Sheets says that in November 2014 Mixter 'calculatedly transformed' his new business partner, Poppy, into a 'Mars Argo knockoff', and 'deliberately copied Mars Argo's identity'.

Pereira cut and dyed her brunette hair blond to match Sheets' color, wore the same style of blue eyeliner and started talking at a higher pitch in her videos to 'mimic Mars Argo's distinctive speaking voice', according to the court documents.

After that, she says, Mixter's harassment and his creation of a 'fake' Mars Ago went hand in hand.

The first Poppy video, 'Poppy Eats Cotton Candy', was released in November 2014.

Weeks later Mixter broke in again, logged into her Facebook account and blocked her new friends, she said.

In January 2015 Mixter broke in a third time, and while 'seemingly intoxicated', he began 'smashing her wine glasses one by one'.

Three months later Mixter allegedly texted Sheets a picture of himself sat outside her door at 2.01am and wrote: 'you probably blocked me so f*** you you b****. You blocked me so I showed up.'

Weeks later, her ex showed up at her front gate and 'punched me in the face', then followed her as she ran inside and locked her door.

Sheets claims he was angry because he had heard she was working with a different video producer.

In May 2015, the lawsuit says, Pereira posted a photo on Instagram wearing Sheets' own leopard print jacket.

Pereira appeared in her ThatPoppy videos wearing very similar clothes to Sheets, including an outfit of a white long sleeve button-down shirt and blue skirt in one video, bunny ears in another, and curtsying in a white dress in a third video.

Sheets also claims that Mixter stole her merchandise ideas.

She says in her legal complaint that in March 2015 she came up with a plan to sell heart shaped candy in a prescription bottle, but that months later Pereira and another artist working with Mixter began selling candy in prescription bottles.

Pereira cut and dyed her brunette hair blond to match Sheets' color, wore the same style of blue eyeliner and started talking at a higher pitch in her videos to 'mimic Mars Argo's distinctive speaking voice', according to the court documents

In November 2014, Sheets claims, Mixter broke into her apartment at night through the bedroom window

In January 2015 Mixter broke in a third time, and while 'seemingly intoxicated', he began 'smashing her wine glasses one by one', Sheets claims. She included the above photos as evidence of the night in her lawsuit

Three months later Mixter allegedly texted Sheets a picture of himself sat outside her door at 2.01am and wrote: 'you probably blocked me so f*** you you b****. You blocked me so I showed up'

Along with similar staging and looks, Sheets (pictured) claims that Poppy also stole the title of at least one of her video titles

Nearly three years after Mars Argo released a video called 'Delete Your Facebook', Poppy (pictured) released one of the same title

Fans on social media immediately picked up on the similarities between Poppy and Mars Argo, but Sheets says it didn't stop her and Mixter from 'keeping going'.

Sheets says this was her 'lowest point' saying she felt 'completely isolated'.

She said: 'I was hiding what he had done to me because I was embarrassed by it and also I didn't want to be associated with it.

'And then a lot of my friends or people who I thought were my friends were working with her [Pereira] which was really confusing and upsetting.

'I kept it all in, I felt stuck and had a feeling like I couldn't move forward, that was the darkest moment.'

In other disturbing alleged behavior Mixter texted Sheets in May 2015 about a seeming drug overdose, writing: 'Just took 11 oxy's laterrrrr'.

The alleged harassment led Sheets to flee Los Angeles in late 2015 and to stop making videos.

She was later diagnosed with post traumatic stress disorder and received treatment. She is still in therapy today.

Poppy, however, has amassed a huge following online for her mysterious persona and strange, quirky videos which have been viewed 280million times worldwide.

The pilot for YouTube Red's 'I'm Poppy' premiered at Sundance earlier this year.

'It's false,' says Sheets, her voice trembling with emotion. 'That's what I don't like about it, I'm true and that's false. I'm all for success and I'm all for making great art, but I'm not for something that's false and fake.

'It is deeply upsetting that she tried to steal my persona. It feels very very weird.'

It was announced on Wednesday that Poppy is teaming up with electro-pop musician Grimes.

While the details of the collaboration are unclear, Grimes posted a series of photos with Poppy on Twitter with the caption 'soon'.

Sheets says that while she doesn't blame Pereira entirely, because she's 'young', she adds that she is willingly dressing like Sheets' Mars Argo persona.

'It seems like she's very aware, she must know what she's doing,' says Sheets. 'A lot of interviews mention me, fans say "Where's Mars Argo?" at her shows and she responds to it. It just seems like some sick joke.'

Sheets is also seeking a restraining order, saying she had not done it before because 'I was afraid it would just agitate him more and that it would get worse.'

Sheets, who was in her mid 20s at the height of the alleged harassment, also concedes she made excuses for him when the abuse first began.

'He was my first boyfriend, I like to believe in the good of people,' she said. 'I believed in our work together. I was in denial.'

Sheets added: 'I don't know what motivates him, I don't know why he does what he does. I just know what's happened to me and what I've experienced.'

She believes the producer thinks he 'created' Mars Argo and can simply move the persona to someone else.

'I can't dissect his chess moves, but yes he thinks that he created me, there's definitely like a control thing there,' she says.

'And his next step was to steal my work and steal my persona and morph some other girl into me.'