Jimmy's parents were zoologists who made a special study of primates. They died whilst on safari in Kenya. The respon­sibility for bringing up Jimmy fell to his older brother Bill who is 12 years older.

Naturally he found it hard, trying to raise a very inquisitive child (then 6 years old) and a mischievous monkey. When Jimmy was away at school, Bill was able to build up his transport business and during the holidays he used to take Jimmy and Mitch with him on his journeys. This also helped Jimmy's education. It was on one of those trips that their plane crashed in the sea only to be rescued by Mike Mercury in Supercar.

Seeing Jimmy as a younger version of himself Mike discussed his ideas with Beaker, Popkiss and Bill. They would look after Jimmy, enabling Bill to carry on with his business without worrying about his younger brother.

Everyone agreed and Jimmy was overjoyed to stay at Black Rock with his newfound friends. Apart from helping where he can around the labs, Jimmy, like Mike, loves aircraft and builds models. He also tries to teach Mitch new tricks.