I have been using a TMNT heroclix repainted and re-based but I just bought a couple of figures from here that are much better sculpts "Turtle Humanoid Miniatures" http://etsy.me/2nY5eOR
https://www.shapeways.com/marketplace?type=product&q=turtlefolk is where I found mine, they're unpainted and a little brittle, but incredibly accurate to what tortles look like in dnd. The guy that sells them has incredible customer service as well, my first one had a brittle sword hilt that didn't stand up to normal use, and he redesigned the whole sword for me.