He had a little help from his friend Lou Seal for his first live performance ever.
He's been watched by millions on YouTube, but on a recent night in San Francisco, viral phenom Keenan Cahill gave the first live performance of his life.
The Giants turned the event into a short film.
Cahill has a rare genetic disorder called Maroteaux-Lamy Syndrome that has stunted his growth. He hooked up with Cody Ross and Brian Wilson who helped organize a fundraising game to help pay for his medical costs.