"Because when they strike it can be that quick that if they're within range, you're dead, you're dead in your tracks. And his head weighs more than my body so it's WHACK!"

This quote by Steve Irwin is describing the power of crocodiles. He is stressing how rapidly they can strike and how deadly they can be. He is also emphasizing the size of the crocodile, noting that its head is heavier than his body. He is highlighting the power of the crocodile by stating that if it is within range, you are dead in your tracks. He is also utilizing the word "whack" to stress the power of the crocodile, as it is a slang term for an effective hit. In general, this quote is stressing the power of crocodiles and how quickly they can strike and how deadly they can be.