That depends. Are you instigating it? No? Then I might say no. I am not gonna hurt someone without reasoning, even barring the legal ramifications. Are you calling me mean names like "poopyhead"? Well, Maybe that would get me considering it. Maybe I'll throw a punch or maybe I'll hit you with a clever zinger again. Throw a punch? Now there's a fight because I can claim self-defense then sue you afterwards regardless. Lunch money is not a factor because I'm too proud of that and I don't know if I can find any nearby flagpoles to support you.
Now as to who would win? I'm pretty big and pretty well trained and am not afraid to fight dirty with anything on hand. But maybe you are a secret martial arts master and you get your kicks from challenging unsuspecting people before beating them senseless. You sicko. I bet you get off on that. But then, maybe the most fight experience you ever had was when you came close to actually hitting Mike Tyson in Punch out and the last time you saw the sunlight is measured in months. Then I would feel bad for hurting you because that's basically unconsenting assisted suicide. But then that might be a facade as the months spent not seeing the sun were spent doing some "Silat-in-a-dark-cave" routine to hone your skills and you were tying to lull me into a false sense of security. Then there's the fact that if I didn't notice your fight starting blow, I could be downed before the fight even begins. Every punch has the chance of being a fight ender no matter. But if it didn't, it'd probably piss me off that I wouldn't treat this with kids glove and just do what ever I can to make sure you don't get a chance to get another possibly dangerous attack off.
And this is assuming that you are a human with a funny internet handle and not some taco-headed hybrid (is that the politically correct term? Mexican-cuisine American?). First of all, there's the fact that Taco-heads are a rare breed, You might be endangered. Don't wanna deal with the laws on that. Then there's the fact that you're head is made of a delicious mexican treat. Maybe it's as flimsy as it looks and making you lean forward is enough to incapacitate you by causing your fillings to drip out (Oh god is that stuff your brain? Is the tomato your hippocampus? What does that make the beans?) but then again maybe the fillings aren't vital and crushing the taco will do little to slow you down. Which is annoying because most of my attacks are focused on the head (Well, when it isn't focused on the other head), so if it isn't a vital area and loss of your taco head can be repaired by a trip to the local Taco Bell, I'll have to focus on body (and lower head) attacks which means it'll take slightly longer to bring you down which means you'll have opportunities to land a lucky shot.
I suppose I could eat your head. I mean, I'm more of a Quesadilla kinda guy myself but if you're one of those Doritos-shell tacos I might consider it. Actually, I lie, hard shell tacos are the bomb. They hold a lot better especially when people put too much sauce on it which makes a normal one feel really soggy but I guess some people are into that. But then, this assumes eating your head would do more than just annoy you. Maybe it'll at least blind you or take away some senses. Unless Taco heads evolved away that weakness by placing their visual and aural receptors in their chests or ass or something. Then there's also the rammifications of what eating a psychic taco would do. Would it give me Psychic powers the same way eating the brains of a computer science graduate helped me fix my laptop? Or would it be like Alpha radiation where once it's inside me, it'll have free range to do damage to my insides. And I'm not just talking about on the toilet later, badabing! Now, my mouth is watering and I don't know why.
So I'm gonna put this down to 8/10 chance I could beat you up but that number might change if I'm hungry and there isn't a Quesadilla nearby instead.