Katy Perry's "Roar" may be pretty catchy, but who knew the pop song could make a nonverbal boy with autism sing?

In a heartwarming video posted on YouTube last week, 8-year-old Jack Robbins sings a verse of Perry's latest single -- and it's the first time he's managed more than a few words on his own.

Robbins' mother, Carla, explained that Jack had been mumbling something repeatedly every day, but they couldn't make out what he was saying.

"[W]e thought it was nonsense, meaningless jabber. UNTIL one day (this morning) we really listened and figured out he was SINGING Katy Perry's 'Roar,'" she wrote on the video's YouTube description on Nov. 6.

For the 8-year-old, who falls within the autism spectrum, communication has always been limited to one-word commands or simple repetition.

"He can only say single words and they're only to get things that he wants," Robbins said during an interview with Texas TV station WFAA. "He's never said anything spontaneously -- anything that he liked or an emotion or a feeling."

Though Robbins knew her son liked music, he hasn't ever been able to express what, specifically, he likes. Now, Robbins knows it's Katy Perry.

Listen to Jack sing a verse of "Roar" in the video above, and watch Robbins' interview with WFAA below.

Also on HuffPost: