Jameson Kessler of Shelbyville, Ind., wears a skeleton costume and calls himself "Marrow Man." He is, after all, his sister Samantha's hero.

This summer, Jameson will donate bone marrow to Samantha, who suffers from a rare blood disorder called thalassemia, NBC's WTHR in Indianapolis reports. The main cure for the red blood cell-destroying condition is a bone marrow transplant from a perfect match, according to Cure Thalassemia.

Enter our hero.

"I'm going to make her feel better and then I'm going to save her when she's in trouble," Jameson said in the segment above.

To raise money for costs associated with the procedure, the kids' mom, Kyrie Kessler, set up a GoFundMe page on Monday, with an anonymous donor pledging to match every dollar donation up to $500.

The family also encouraged followers on Samantha's Facebook page to purchase buttons that read, "I wear [green ribbon] for Samantha a BMT warrior."

According to bethematch.org, the donation process often involves doctors extracting the marrow from the back of the pelvic bone with hollow needles. Donors, who are anesthetized during the operation, can experience discomfort afterward.

Sounds like a job for a very brave 3-year-old. Way to save the day, Marrow Man.

Those who would like to donate can visit the GoFundMe page.

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  • Started A Youth Soccer Program In Haiti

    When <a href="http://www.huffingtonpost.com/2011/07/14/kona-shen-soccer-inspires-haiti-youth_n_899410.html#s309105" target="_hplink">Kona Shen</a>, 23, saw the energy that Haitian children had for sports, she realized that she could utilize that energy to make a difference. She founded <a href="http://goalshaiti.org/" target="_hplink">Global Outreach And Love of Soccer</a>, or GOALS, which works to provide youth leadership, community development and environmental awareness through sports teams and summer camps. "Kids here don't even need a ball or cleats to excel in soccer," she said. "They have a chance when playing soccer to really excel even when they have no resources ... it's a really powerful way for kids to regain and maintain normalcy in their lives." To get involved, <a href="http://goalshaiti.org/howtohelp/" target="_hplink">click here</a>.

  • Wrote An Advocacy Book About Epilepsy

    For as long as he can remember, <a href="http://www.huffingtonpost.com/2011/07/18/huffpost-greatest-person-evan-moss-epilepsy_n_901987.html" target="_hplink">Evan Moss</a> has been suffering from epileptic seizures. One semi-successful brain surgery and thousands of seizures later, Evan, now 7, wrote a book about his epilepsy to raise money for a seizure dog, which will alert help if Evan is having a seizure. To buy Evan's inspirational book, My Seizure Dog, <a href="https://www.createspace.com/3626033" target="_hplink">click here</a>.

  • Started A Food Bank For Pets

    When <a href="http://www.huffingtonpost.com/2011/10/05/georgia-man-starts-nonpro_n_996562.html" target="_hplink">Tom Wargo</a> first introduced the idea of a food bank for pets, food banks thought he was crazy. Now he gives away 600,000 pounds of pet food a year at his four Georgia locations -- while managing to help food shelters focus on what they do best: feed people. "[People are] not going to let their animals starve, they're not going to kill them at the pound, so they're going to feed them, just like if you have kids." To learn more about Wargo's pet food banks or get involved, <a href="http://daffyspetsoupkitchen.info/" target="_hplink">click here</a>.

  • Founded The Iraq and Afghanistan Veterans Association

    In 2004, <a href="http://www.huffingtonpost.com/2010/11/10/greatest-person-of-the-da_10_n_781843.html" target="_hplink">Paul Rieckhoff</a>, an Iraq War veteran, founded the <a href="http://iava.org/" target="_hplink">Iraq and Afghanistan Veterans Association</a>. The nonprofit is the nation's largest for Iraq and Afghanistan veterans, with some 200,000 members -- and focuses on awareness, advocacy and assistance for soldiers returning from war. "I had the support of my family, but I still felt alone as an Iraq veteran," Rieckhoff said. "And I didn't want others to feel the same." To get involved, <a href="http://iava.org/take-action" target="_hplink">click here</a>.

  • Tours The Country Speaking Out Against Bullying

    <a href="http://www.huffingtonpost.com/2011/10/13/woman-and-dog-with-simila_n_1009024.html" target="_hplink">Gabrielle Ford</a> suffers from a degenerative neuro-muscular disorder that weakens her body's muscles. It's an illness that she tried to hide for many years. That changed when she got a dog, Izzy, who was eventually diagnosed with a similar muscle-degenerating disease. Having been a victim of bullying, Fords toured the country with her dog, speaking out against bullying, and inspiring others to do the same. "I didn't plan on affecting people, it just happened with the life story or hand I was dealt," Ford said, "One person said, 'you didn't find your meaning and purpose in life, it found you and you're a hero to thousands of students bullied in American schools every year.'" To buy Ford's book and donate to her cause, <a href="http://www.gabeandizzy.com/" target="_hplink">click here</a>.

  • Started 'Pay What You Can' Panera Bread Restaurants

    <a href="http://www.huffingtonpost.com/2011/06/15/huffpost-greatest-person-ron-saich-panera-cares_n_877691.html" target="_hplink">Ron Shaich</a>, founder of <a href="http://www.panerabread.com/" target="_hplink">Panera Bread</a> is more than just a fast food mogul. In the last few years, Shaich has opened three Panera Cares restaurants, built around a "pay what you can" model. "A lot of investors really didn't like this idea back then," Ron said. "But I saw it as a vehicle to, shall I say, serve real food to real people. At the time, fast food had basically become self-service gas stations of the human body. We wanted to give people food they could respect."

  • Helps Feed Hungry Childen

    <a href="http://www.huffingtonpost.com/2010/11/03/greatest-person-of-the-da_6_n_778520.html" target="_hplink">Bruno Serato</a> is known for more than just serving celebrities at his Anaheim, Calif. restaurant, <a href="http://www.anaheimwhitehouse.com/" target="_hplink">Anaheim White House</a>. Instead, he's made a name for himself feeding "motel children" free pasta seven days a week. On average, Serato and his restaurant feed about 150 children, and have given away 245,000 meals to date. "A customer once asked me, 'Bruno, how can you afford to do this?' I said, 'How can I afford to stop?' This is my passion. If I could not do what I do every day, I'd be devastated." To help Serato feed hungry children, he asks that pasta donations be brought to his restaurant, or visit the nonprofit he began to help raise funds, <a href="http://www.thecaterinasclub.org/" target="_hplink">Caterina's Club</a>.

  • Helped Build A School In Kenya

    Officially, <a href="http://www.huffingtonpost.com/2011/09/09/margo-mcauliffe-retired-t_n_955932.html" target="_hplink">Margo McAuliffe</a> has long been retired. But in reality, she's nowhere close to retirement. When she finished teaching high school math in 2003, she took a trip to Kenya and decided to help fundraise for a new school there. A million dollars later, McAuliffe had helped build a school. So far 17 girls have graduated high school, and 46 more are expected to graduate next year. "It gave me helpful insights. I took away that I -- we -- need to appreciate the education that we have here." To get involved and see the school's progress, <a href="http://kenyahelp.us/home.html" target="_hplink">click here</a>.

  • Helps Answer Letters To Santa At Christmas

    Thousands upon thousands of Christmas wish lists addressed to Santa make their way to <a href="http://www.huffingtonpost.com/2011/12/25/pete-fontana-santa-brings_n_1166911.html" target="_hplink">Pete Fontana's</a> hands each year. He is the "chief elf officer" at the New York post office, where he readies the letters for donor pick-up, then delivers the presents that volunteers bring back. "That's the best part, is meeting these people," Fontana said. "They energize me."