.177 caliber airgun pellet damage?

Ok, so what if an intruder entered my house when my parents weren't home. I am 14 years old (boy) and I have a .177 cal. pellet gun that should shoot at 600 fps. I use it for plinking (shooting cans and plastics and such), not shooting animals for whatever reason ever; I wouldn't do that. What I would do is shoot an intruder, so what kind of damage would it do? I would also have my trusty knife ready but the airgun would come in firsthand, also were talking standard crosman pointed pellets. Request any additional details please.