YouTube's Greatest Hits

There is still one YouTube star left to meet—Tyson, the skateboarding bulldog! Tyson runs out and coasts back and forth across the Oprah stage on his skateboard, cutting corners like a pro.

Visit Tyson backstage after his Oprah Show appearance.

Tyson's owner, Jim, says he didn't have to teach his athletic pup a thing about riding a skateboard. "Tyson is self-taught," Jim says.