Jason Rockefeller is a former actor, who starred in several SyFy Channel and direct-to-video movies. This wasn't steady work, so he also worked part-time as a 911 operator, and went to wrestling school on the side.
One evening, he took a call from a boy claiming to be a robot whose creator wanted to dismantle him. He reported it as a prank. Two days later, he was fired, because it turns out the boy was autistic and was being abused by his caretaker.
Guilt-ridden, Jason visited the boy in the hospital. The boy's name was Peter, and when he first woke up, he immediately started calling Jason "Uncle Rocky", for reasons that Jason has never uncovered to this day. Jason drew on his experience as an actor to play along with Peter's delusion.
A few years later, FIW was graced with the first appearance of Uncle Rocky, and his pal Robot Pete. While often labeled as "children's show hosts", both Rocky and Pete are quick to point out that their act is "for friends of ALL ages!"