Despite having the word 'banter' in its name, someone described as a Bantersauross have no banter whatsoever. In fact, they are usually the brunt of the jokes.
The outward display of affection between two intimately friendly parties by extreme piss taking, savage in nature.
Usually characterised, and generally understood by the rule of thumb that the more offensive and deftly aimed that the ribbing is, the greater the respect or underlying fondness that exists.