Stampy-footed and vicious but cute and sexy yet ('lovably') annoying fiery-haired princesses.
hmm...
Weapons with overly cheesy (wince-worthy) names, too.
Ah, anything with an overly cheesy name.
So really my bane in a fantasy novel would be a vicious, cute, sexy, 'lovably' annoying, stampy-footed, fiery-haired princess called Willowblossom or Elfstar or whatever, wielding a hugely powerful awesome magical kewl legendary Piece O Death that goes by the name of Whisperdeath or some such.
Yeh. That'd do it.
Oh, too the cutesy wittle critters that waddle/paddle/flap/sproing/bound/etc. around for no other reason than to score 'cute points' with potential marks, ah readers that is.