Well, not really. I never like to give out too many details about what the players are up against. In my current campaign I described these guys as short, lizard-like humanoid creatures. They are your basic low hit dice creature (from 1 to 4 hit points as convenient). When you kill one, he blows up for d4 points of damage. Pretty gruesome, but it does tend to cut back the wholesale slaughter for low level characters.
Which brings up an interesting point. Monster hit points. There are basically two kinds of monsters in my realm. Monsters that are intended to put up a fight, and "monsters" (typically guards and townsfolk) that do not. Monsters intended to fight get 10 hit points per die. Easy math, and it is similar to your average player character. Monsters intended NOT to fight only get 1 hit point. Easy to accidently kill off the townsfolk, best be careful where you swing that axe.