Dndspeak is a site that features a number of RPG-oriented lists and generators, including an excellent Dwarven Insult Generator.
YOU FOUL, ROCK-BRAINED, CAVEFISH SUCKER!
YOU LOATHSOME, DIRT-RIDDEN, RUST BUCKET!
YOU SMELLY, DUNG-SNIFFING, RUST EATER!
YOU FIENDISH, FUNGUS-SNIFFING, TOSSER!
YOU FRIENDLESS, ANVIL-DROPPING, DROW LOVER!
YOU SCRAWNY, ARMOR-BITING, WRETCH!
YOU FESTERING, ANVIL-HEADED, WINE DRINKER!