Colt Wilson is 3 years old, proudly plays with girls and stuffed animals until you cross him.

The 3-and-a-half foot tall, 34-pounder hits like his idol, J.J. Watt, family said.

“He’s tiny,” said Cortni Wilson, Colt’s mother. “He’s little, and he beats up on his older brother and doesn’t let anybody run all over him.”

Colt also just rang the end of treatment bell on cancer, too. He told KHOU 11 News it felt “wow,” because “I’m done with chemo(therapy).”

However, when you look at photos snapped of the moment, there are more than smiles and hugs. You can also see tears.

“Hearing that sound (of the end of treatment bell ringing at Texas Children’s Hospital) was the biggest relief as a mom to know that (Colt) had made it that far,” Cortni Wilson said. “It’s still a long road but the biggest hurdle was won.”

One month after Colt’s third birthday party, doctors discovered a tumor with Rhabdomyosarcoma. The cancer spread into his prostate. Colt’s condition is rare.

“He is one of five children in the United States right now that has it in his bladder and prostate,” Cortni Wilson said.

Her son survived 12 and a half weeks of chemotherapy and 28 consecutive days of radiation targeting Colt’s prostate.

Much of the process can be seen through Sherina Welch’s camera lens on Facebook. Her “More Than 4 Photo Project” documents six families fighting childhood cancer and shines light on research funding disparities. A photo of the Wilsons went viral.

“I think it’s just empowering because it’s helping these families feel like they’re not alone,” Welch said.

The Wilsons savor the moments Welch captured as Colt finished treatment.

“I was just overcome with emotion and proud of him for never giving up,” said Preston Wilson, Colt’s dad.

It seems their little fighter is inspiring his family to battle, too.

“It’s made me want to fight for more and more kids so that one day (researchers) know what caused (this cancer),” Cortni Wilson said. “One day they (will) know they can save every kid who has this.”

Colt has to complete 3-month scans but hopes to ring the end of treatment bell once more when he defeats cancer.