A 12-year-old was surprised with his first bionic arm by YouTube megastar Jimmy Donaldson – known as MrBeast.
Kai Pollnitz, who was born without his right hand, received the custom-built prosthetic at an Open Bionics clinic in Austin, Texas.
MrBeast, 27, personally visited Kai at the clinic, where he presented him with the advanced Hero PRO arm from Open Bionics.
“At first I couldn’t speak,” Kai said.
The gift came after years of dreaming of having a bionic arm to help him perform everyday tasks and feel more confident at school.
Kai hopes others learn from his experience that perseverance and adaptability can overcome any obstacle.
Kai, who lives near Austin, began facing teasing and bullying over his condition in middle school.
For years, Kai had hoped for a bionic arm that would allow him to do things many of his peers take for granted — tying his own karate belt, cutting his food, riding a bike and participating more confidently in daily life.
While researching prosthetic options, his family discovered Open Bionics, a Colorado-based company known for its advanced multi-grip bionic arms.
The arms feature customizable covers created in collaboration with major brands such as Disney, Marvel, Star Wars, and Call of Duty.
Kai’s insurance, however, would not cover the cost of a myoelectric prosthetic.
“We tried crowdfunding and did everything we could as a family,” said his adopted mother, Charlotte Pollnitz.
“It was humbling to make a video asking for help, but we just wanted Kai to have a fair chance at life. Every donation brought him hope.”
Despite limited progress raising funds, Charlotte brought Kai to the Open Bionics clinic in Austin for an evaluation.
“Even before we could afford it, Open Bionics treated us like we mattered,” Charlotte said.
“Anytime I had questions, someone answered with real advice. We knew we were in capable hands.”
During the appointment, Kai tried a bionic arm for the first time.
“We both cried,” Charlotte said. “He has never been able to use that hand, and suddenly he could.
“Watching him pick something up and drink from a cup with his right hand felt unbelievable.”
Kai described the experience as “fantastic,” but remained realistic about his family’s situation.
“It would be so great to have a right hand, but I’m fine with waiting,” he reportedly told his mother.
Unknown to Kai, his story had already reached MrBeast, who decided to intervene.
Kai returned to the clinic believing he had a routine follow-up appointment.
Instead, MrBeast walked in carrying a custom Hero PRO bionic arm designed specifically for Kai, featuring personalized MrBeast covers with the creator’s signature blue-and-pink panther and Kai’s name.
“He was completely in awe,” Charlotte said. “He kept whispering, ‘Mama, is this real? Is that really MrBeast?’”
Kai added: “At first I couldn’t speak. I never thought I’d meet him in real life.”
Tilly Lockey, an Open Bionics ambassador and bilateral bionic arm user, was also present for the reveal.
“Being part of this project with MrBeast feels full circle for me,” she said. “I was once the kid being surprised with a bionic arm, and now I get to be there for Kai.
“I know exactly how life-changing that moment can be.”
The Hero PRO is among the most advanced multi-grip bionic arms available, developed with input from more than 1,000 users over four years of research.
The fully wireless, water-resistant device can lift up to 55 pounds, is touchscreen-compatible and features a fully articulating wrist with a quick-release system for activity attachments.
With his new arm, Kai is now completing two-handed tasks for the first time — from playing basketball to helping out in the kitchen.
“We never imagined something like this would happen for him,” Charlotte said.
“It’s once in a lifetime, not just because he met his idol, but because he now has a bionic arm that will change his life.”
Samantha Payne, co-founder and CEO of Open Bionics, said: “Seeing him receive a Hero PRO has been meaningful for everyone involved.”
When asked what he hopes others take away from his experience, Kai offered simple advice.
“Don’t let people put you down,” he said. “Nothing’s going to stop you. You just learn an alternative.”


