Hoser is a euphemism for another word. The word is f*cker. As shown above, it can be used in either a hostile or a friendly manner, depending on the context and the tone of voice, etc.

Hosehead is similarly a euphemism for f*ckhead.

Shane, he the famous oaf of Blind River, has his own substitute: fliphead.

With Shane, it's "Flip you!!!" "You are totally flipped, man!" "Flip OFF!" "Flip ME!" (when things have gone seriously wrong) and such typical expressions...