A Bo Bo Head is a goof ball, loser or dweeb.

a term of affectionate derision used to gently dope slap a mate, colleague, family member or imperfect stranger (the imperfect stranger use will be a dope slap of some force and typically not gentle) when they stray too far outside of acceptable social convention as determined by the user of said "bobohead" term; not to be used indiscriminately lest the term become overused and in fact, boboheadish.