I've never been good with names; off the top of my head "Tanks", on account of their thick, armor-like outer shell, "Biters" or "Shearers" because of their long, sharp... thing. I can't think of the exact word, but I think you know what I'm talking about? Hopefully. The sharp, stabby-cutty thingy. Mandible? Maybe.<br/><br/>Err, anyways, I'm bad with names. As for size and stuff, I see them as having the aforementioned sharp things, very tough shells (probably requiring non-physical or crushing blows to penetrate), and being about two feet long, full grown; with the rest of their body scaled to that.