PORTLAND, Ore. (KOIN) — Otto Stuckman loves dress up and dragons. He just turned 5 on December 29 and was enjoying kindergarten and projects with his dad.

At the beginning of January, Otto started having headaches and he said his legs hurt a little bit.

GoFundMe for Otto Stuckman

“But we had been tubing on Mount Hood,” his mother, Emily Stuckman, told KOIN 6 News.

The pain persisted throughout the month and after several trips to the doctor, Otto was admitted to Doernbecher Children’s Hospital.

That’s where his parents learned he has Stage 4 neuroblastoma.

“I mean, he was completely fine a month ago, completely fine,” Emily said. “And then, you know, for him to go downhill so fast.”

His parents, Emily and Brandon, have been with him non-stop.

Otto Stuckman in an undated photo posted on a GoFundMe site by his mother, Emily Stuckman in January 2016

“He told me he can’t wait until it’s summertime when we can go back to the Renaissance Fair,” she said.

“He’s such a warm and friendly little guy and he means the world to me,” Brandon said. “I would do anything to help him.”

Family members have been at Otto’s side around-the-clock. Even a quick trip to get supplies at Target last week was cut short.

“I’m standing in Target and (Brandon) called and he’s, like, ‘They want to talk to you,” Emily said.

Doctors had found a brain tumor.

Otto is now recovering from brain surgery as he continues to fight cancer.

“He’s just an awesome guy,” his dad said. His mom added, “I would trade places with him in a heartbeat if I could.”

They also have a message for other parents.

“Follow your intuition. If you feel that something is really wrong, make sure that you advocate for your child.”