Mikey is pictured at left with Paul Sr. and Paul Jr.
Michael "Mikey" Teutel is Paul Sr.'s youngest son and brother to Paul Jr. He reached celebrity status while working for the OCC as a secretary/custodian.
To understand Mikey and his contribution to the show American Chopper read this description written by Wikipedia.com:
"His presence also seems to have a calming effect on his father, who almost never shows the same sort of frustration he feels for Paul Jr. Mikey is often able to antagonize his father with little consequence, perhaps in the ancient tradition of being the youngest family member and therefore allowed to get away with behavior his older siblings would never have. He is now a major and popular part of the show and now appears at promotional events for O.C.C., as well as continuing working for the family business in his new job as a webmaster. He is also known for his poor driving skills, as he demonstrates in the series on one occasion where he managed to drive his father's truck into a pond while presumably showing off for a friend, and another where he fails the driving portion of his motorcycle license exam (which, as was indicated, was not the only time). He also backed up a truck hitting his father's SUV, and damaging the bumper in the past." (http://en.wikipedia.org/wiki/Michael_Teutul)