Yes, of course it can be entertaining!
As far as pure evil goes -- I wouldn't do this again, it was just once when I was just getting started with doing cold approaches recently -- the worst I've done was approach a somewhat older woman (35-ish?) who was standing by herself at a table near the bar. The people she was there with were kind of ignoring her. I approached and she said she was just fine hanging out by herself. Since I wasn't terribly interested in the first place, and since I figured I should *try* being a total jackass for just once in my life, I replied: "OK, have it your way. Give it a few years and you'll be an old cat lady in no time!" Her response: "Did you actually just say that???" I laughed and walked off.
I know, I know, totally evil and spiteful, but I think it finally set off the "what's the worst thing that could happen" circuit in my brain. Even though I was a total jerk *intentionally*, nothing really bad came of it. So clearly if I'm anything *less* than a total jerk, approaching a woman is not going to cause the world to end.
Now, a true guru would be able to use a line like that and *still* pick up the girl...