I've done a few with my PCs over the years, I had a wizard that would collect a finger from every enemy he killed, then he'd put them on a necklace and wear them around his neck (something similar was done in "Your Highness," but not with fingers...and was very funny in a crude sense).
Great until someone cast undead...damn worn fingers!
Mine, Halfling Ninjas called...The Feet! Based off Marvel comic's The Hand and wrestling. Attacked as a team, with acrobatic moves used smoke bombs (the smoke rose till it was about three feet off the ground). Their favorite move was always to attack below the belt, head to crotch, kick to crotch, flying kick to crotch, tieing shoes together, super glueing weapons...