Off the absolute top of my head there's the redcap. Depending on the material it can be depicted as a gnome, goblin, or kobold with a jaunty looking red hat (generally long and pointy like a gnome hat or like Link's hat in Legend of Zelda).

It keeps the hat red by dying and regularly re-dying it with its victims' blood.

There's also a number of depictions of pixies as essentially flying piranha.

But this sort of mythology isn't some deep secret, it's everywhere outside of the kid friendly/disney filtered stuff. I'm sure a simple search will net you tons of content.