Dungeons & Dragons for the Daydreamy Kid
Many Dungeons & Dragons character miniatures have protrusions on them, be it a horn or a sword or a mace, so using jump rings and pony beads (you know, the plastic ones), you can place one bead per jump ring and close it up.
Red = bloodied. Ice blue = frozen. Yellow = dazed. Individual characters who can "mark" monsters pick their own signature marks, and these can even be embellished if needed, or include glass beads for extra pizazz!