BITWRATHPLOOB is a modified acronym for "bucktoothed rope-armed troll-haired pantsless wood bear". Since the actual acronym, BTRATHPLWB, isn't very pronounceable, other letters were added to make it more compatible with English.
A South African term used to insult British people. The term implies the British person is worth a "wank" or is a "wanker". To qualify, a cup of tea or bad teeth must be present.