This was the headbutt heard around the world. The world cup to be exact.
You can almost hear his skull crack on this headbutt.
Tough guy gets knocked da F*** out by a smaller kid. Now that's what I call using your head!
A frustrated basketball player headbutts the hoop and paralyzes himself.
Headbutting glass is probably not the smartest thing to let your goat do.
Brittany Furlan gives head for the first time.