She wore a blue ruffled dress for the occasion, and pulled a tie out of her brother's closet to drape around 'Danny's' neck. She also bought him a boutonniere to match her own corsage.
Over three weeks later, though, the joke has taken on new life. On May 4, DeVito's It's Always Sunny co-star Rob McElhenney took to Instagram to share some new pictures.
'Hey Allison,' he wrote. 'I heard you took cardboard Danny to Prom. What a coincidence. He took cardboard Allison to Paddy's...'
In the post, he included one of Allison's photos — as well as one of DeVito on the show's set, hanging out at the bar.
DeVito looks amused, pointing to a life size cut out of Allison in her light blue prom dress.
Soon after it was posted, Allison herself saw the image, tweeting her disbelief: 'I am shooketh.'
'Thank you SO, SO MUCH @RMcElhenney and @DannyDeVito for fulfilling my dream of visiting Paddy's Pub from @alwayssunny!!' she added.
Interestingly, the whole thing almost didn't happen. Allison told the New York Post back in May that she'd considered other celebrities for her date, including Bill Nye the Science Guy.
'But many of them would [have required] ordering a custom-made cut out, and I'm not about that money life, if you know what I'm saying,' she said, adding that she she found a 'shockingly wide variety' of premade cardboard cutouts of the 'hilarious' DeVito already for sale on Amazon.
She spent $100 on the cut out itself, and duct-taped it to a $20 plastic scooter so she could pull him around with a leash.
In addition to earning her fans online, Allison's cut out date was also a hit with classmates, who lined up to take photos with him. But she admitted that she wouldn't let anyone else dance with the cut out, because she was worried he would get broken.
'Making things work with a human date can be so exhausting,' she told the Post. 'Danny's not like that. He just goes with the flow . . . We never argue, never fight.
'Plus, he treats me the way a woman should be treated.'
In the fall, Allison plans on attending Gettysburg College to major in film and media studies, but it looks like she is already quite media savvy. After prom, she made a video about the experience, which she shared on her YouTube channel.
In the clip, she explained how the whole idea came about, noting that she was 'having trouble finding a prom date.'
'It seemed like all the good guys were taken, and all the ones that weren't taken I wasn't really interested in,' she said. 'Until one day, I had this idea. What if I just bring a cardboard cut out of Danny DeVito to prom? So I did.'
Knowing that stories like this end up on the news 'all the time,' Allison revealed that she had reached out to ABC News to see if they wanted to do a story on her.
After sending in photos and videos, she ended up making the local news, and her prom pictures quickly went viral.
'This is like the highlight of my year,' she admitted.
