Five-year-old who wrote his own obit gets celebration of life with bouncy houses and more

The death of a child is so tragic, so painful, that there's typically not anything to smile about.

But Garrett Matthais, a five-year-old from Van Meter, Iowa, who died on July 11, managed to put a smile and more than a few tears on the faces of the thousands who have read the obituary he himself helped pen.

The obit appeared in the Des Moines Register. Garrett -- also known to those who loved him as "The Great Captain Underpants" -- answered a series of questions such as his favorite people, the things he hates the most, and what will happen when he dies.

For the record, he is "going to be a gorilla and throw poo at Daddy!"

"We did't believe writing a 'normal' obit would so his personality justice and we wanted to ensure the reason he died -- cancer -- was highlighted," his mother, Emilie Matthais, told Good Morning America.

His parents wrote in his obituary that "Garrett endured nine months of hell before he lost his battle with cancer." His mom told "GMA" Garrett was diagnosed with Rhabdomysosarcoma in September 2017.

But, he "never lost his sense of humor," the obituary said.

That's clear from many of the things Garrett wrote. Among the things he hates: Pants.

In some places, the obituary is much sadder. Also among the things he hates, "dirty stupid cancer, when they access my port, needles, and the monkey nose that smells like cherry farts."

The obit was written from a series of questions posed to Garrett by his mom and his dad, Ryan. It was inspired, his mom said, by a Mother's day project Garrett's 6-year-old sister Delphina brought home from kindergarten.

"When we finished it and read it out loud my husband and I both laughed and cried," Emilie Matthais said. "We reminisced a lot about G and how much this obit perfectly captured his personality. We were both thrilled we had jotted down some of our conversations and were able to us his words."

Garrett did not want a funeral. He told his parents he "wanted to be burned like Thor's mommy." He also wanted "five bouncy houses (because I'm five), Batman and snow cones."

He got it. His parents held a celebration of Garrett's life, complete with fireworks in honor of the little boy who has now moved so many through his words.

"I think Garrett would have had a blast," his mom said. "He would have loved all the super heroes and bouncy houses. I think he would have been awed by the archer and his shooting skills. He would have loved to watch his boat burn and see the beautiful fireworks. Thor and Batman would have been the highlight for him."

Funerals, his mom said, are not the way an "awesome kid like Garrett" should be remembered.

"We are so grateful to the many doctors, nurses, child life specialists, musicians, art therapists, and volunteers that worked tirelessly to cure Garrett of his cancer," they wrote near the end of the obituary. "The reality for Garrett and so many other children is pediatric cancer is an ugly, nasty beast that leaves a path of destruction. For Garrett and many others before him - cancer kills. Those that are 'lucky' enough to survive endure long term debilitating side effects and the constant fear of relapse. We will fight for a cure until no other kids are robbed of their childhood, no other siblings lose their best friends, and no other parents have to bury their babies."