Alexander made cameo appearances in the second season of '' Curb Your Enthusiasm '' , playing himself , and appeared in the seventh season of '' Curb Your Enthusiasm '' along with the other three principal '' Seinfeld '' cast members . He had a part in the ABC sitcom '' Dinosaurs '' , as Al " Sexual " Harris ( who frequently engaged in sexual harassment ) as well as other voices . Despite a successful career in film and stage , Alexander never managed to repeat his '' Seinfeld '' - level of success in television . 2001 marked his first post - '' Seinfeld '' return to prime-time television : the heavily promoted but short-lived ABC sitcom '' Bob Patterson '' ( which was canceled after five episodes ) . Alexander partially blames the lack of success on the mood of the country after 9/11
9/11
September 11 attacks
Jason Alexander