Here are some options:

Shakespearean Insult Generator. Examples:


Thou currish sheep-biting minnow!
Thou rank sheep-biting nut-hook!
Thou qualling full-gorged coxcomb!
Thou mammering beef-witted lewdster!


Here's a link to a tailorable insult generator. Sample output:

Technically, you're a man. Technically, so is a she-male Ladyboy from Thailand. In reality, you're nothing more than a pitiful gin-sodden excuse for anything other than a rancid fuckweasle! Married, eh? Since when did brother and sister marriages become legal? Average looking, my ass. You're uglier than the south-facing end of north-bound mule with a ruptured ulcerated fly-covered rump. You're a neo-Nazi, fundamentalist militant Republican-voting mega-asshole scumbag. You four-eyed, cerebrally-deluded, Einstein-impersonating, pseudo-intellectual nerdturd with a head full of misfiring synapses. Like your height, everything about you is average; except your stench - which is overwhelming. Your weight may well be proportional, but you've got cellulite that makes sumo wrestlers look anorexic. Professional, my ass. You couldn't win a cigar after giving birth in a tobacco field in Havana, you clueless, uber-incompetent fuckwit. I like that outfit you're wearing. You should hang on to it. It'll probably come back in style some day. What you are - besides a pitiable little carnival freak - is a watery bowel movement bubbling back up to the surface after a pregnant water buffalo farts in a muddy river.

There are a lot of choices out there when it comes to insult generators. A Google search on "insult generators" returned over 7000 hits. Enjoy, you lazy sack of ....