Brayden Denton, a 5-year-old from Newton County, Ind., died of a brain tumor earlier this month.
Brayden had been fighting brain cancer since he was diagnosed on April 20, 2013.
His mother told WLFI that her son "always had some superhero with him" during treatment.
"I felt like I was honoring him in a way that if he was looking down on us he would be happy," she said.
Brayden's favorite superhero was Spider-Man.
The picture has had hundreds of shares on Facebook. Staci has donated her son's tumor to medical research.
The family is trying raise awareness for Diffuse Intrinsic Pontine Glioma, which is terminal for 100 percent of the patients.
"This cancer does not have a survival rate," Cory said. "Even leukemia is survivable. This one is not."