Halloween was all treats, no tricks for 10-year-old Julian Perez of Arlington.
"I went as Amari Cooper," Perez said, explaining his Halloween costume.
Perez injured his leg last year and then was diagnosed at Scottish Rite for Children with osteosarcoma, a cancerous bone tumor in his leg. Doctors amputated Perez's leg and fitted him for a prosthetic.
"I'm going to be completely honest with you. I first heard about it, I was thinking about having a prosthetic," Perez said. "Each time I feel sad, I think about, like, how I'm going to play football again."
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Perez's favorite football player is the Dallas Cowboys' Amari Cooper.
"I like Amari Cooper because he's really nice and he's super cool," Perez said.
"Whenever they said they're making his prosthetic, they said it would be ready before Halloween, and as soon as he found that out, he said, 'I have to be Amari Cooper,'" Julian's mom Vianca Perez said.
So when Cooper signed Perez's prosthetic leg and recorded a personal video message to go with the pre-Halloween unveiling of the surprise, it made the 10-year-old's day.
"At first I thought it was a fake," Julian Perez said. "Then I saw the video."
"When he saw the signature," Vianca Perez said. "He went from 1 to 100. Like, his face it up. It was insane!"
"I feel like each time I wear it or put it on, I feel like I'm special," Julian Perez said. "Because I go the signature and the leg is just really cool!"
Perez is in remission and training on his new prosthetic. In less than two weeks, he's up to wearing it two hours a day.
"He rubs off good energy on everyone," Vianca Perez said. "I love that about him."
"I want to be an NFL player," Julian Perez said. "I want to be on the Cowboys team."