A complete and utter twat, dickhead, plonker for whom the words 'fanny' and 'wanker' just dont elicit the right level of bastardness of said person by themselves but when put together it totally describes the person and their pointless existence.
A referee from Glasgow at an Old Firm Derby Game when "That ref used to go to St Mungos School, haw ref ya fannywanker the ball was out!"
If you're looking for a good wank, get an erection and get in the bath. Fill the bath. Fill the water up to the helmet of your penis, then get a fly and pull it's wings of and put it on the end of your penis. Because the fly can no longer fly and it can't swim, it will run around in circles on the end of your penis and cause you to ejaculate.