sly old fox
A friend of mine would become so apoplectic with rage that he suffered from a kind of expletive blindness and could manage to splutter out only the most feeble insults. His all-time classic was "You're nothing but a sly old fox", closely followed by "You're just an old bagpuss".
written by Ha*k , approved by Log

"You pogglesnatch!" was the anguished wail of Bill Murchison whenever he was wronged.
Other scathing put-downs that he came out with were 'grankboggle', 'bogglewonk' and his finest hour - 'you saxophonist'.
(A brief googling shows that this website is the only one in the world to contain the words grankboggle or bogglewonk. What a coup! - Log)
written by Po*gle*na*ch*, approved by Log

I had a similar experience with the class fleabag. I called him something along the lines of a filthy cunt, as he'd had the temerity to touch me (thus giving me his fleas). I was alarmed when he ran to tell the teacher, who asked what name I had called him. The stupid pikey fleabag looked blank for a moment, then said: "Pussy-cat." The teacher just smiled indulgently, and I got off scott-free. (Except for the fleas, obviously).
written by an*nym*us *ser, left hanging by Log