Of course. I meant as opposed to a utility knife.
In either case, I'd caution you against getting a knife similar to that hunting knife you showed me before—the one with the gut hook. This is because, a knife like that is designed exclusively for skinning animals while hunting. Yes, it can obviously be used for cutting other things, but if you're using a knife defensively against an attacker, you'll very likely want to use thrusting motions. If you were to use a knife with a gut hook, chances are it would get stuck if you were to thrust. You definitely don't want that. Instead, opt for a blade structure that can slip in and out easily. Perhaps a tanto-point.
And of course, ideally you'd want a fixed blade for self defense, simply because its construction is better suited for combat. But folding knives are better than nothing. Check out this list and see if there's anything that catches your eye. Most of these categories are for fixed blades, but there are some folders in there as well. A word of caution, though; I recommend you stay away from any Gerber knives. That manufacturer has had way too many recalls for me to trust any of their products anymore. They're known to break often.
http://www2.knifecenter.com/knifecenter/index/specops.htmlOf course, I do not condone using any knife on another living thing, except as a last resort. And if you absolutely must use it, attack to wound, not to kill.