Jamie is a minor character who appeared twice in the original Ben 10 series. He was never named in the show, but he is listed by name in the credits.
Jamie is a chubby kid wearing a light beige T-shirt under a greyish-blue shirt. The shirt has a pocket with a pen in it. He has black hair which is slightly unkempt. He has blue, round shaped glasses. He is wearing blue jeans and grey shoes. He has a wristwatch on his left arm.
Leaving Madison Elementary School at the end of fourth grade, Ben caught Cash and J.T. bullying Jamie and went to intervene. This only resulted in both the would-be hero and the victim getting suspended from the nearby tree by their underwear. Ben tried to explain that he was only trying to help, but Jamie rebuked him as his "help" had only complicated things further. When Grandpa Max showed up to take Ben on their camping trip and subsequently helped him down from the tree, he most likely helped Jamie down as well.
In an alternate timeline, during lunch the following school year, Cash and J.T. attempted to swipe Jamie's strawberry milkshake. When Ben told Cash to let the shake go, he did. But this sudden move on Cash's part caused Jamie to lose balance and accidentally catapult his drink onto Ben.