Heat oven to 200°F. Line two large baking sheets with parchment paper. In large bowl, combine egg whites and sugar. Place bowl over pot of gently simmering water, and whisk constantly until sugar dissolves and egg mixture feels warm to touch, about 5 minutes.
Remove bowl from water bath, and with electric mixer on high speed, beat in peppermint extract. Continue beating until very stiff peaks form, about 8 minutes. Spoon mixture into large resealable plastic bag, and snip off corner.
Pipe bone shapes, 4 to 8 inches long, onto baking sheets. Bake until crisp throughout, about 65 minutes. Cool completely. Store in airtight container for up to 3 days.
Serve meringues partially buried under ground chocolate graham crackers, if desired.