"If you start throwing hedgehogs under me, I shall throw a couple of porcupines under you"

This quote by Nikita Khrushchev is an amusing method of saying that if someone is going to be aggressive or hostile towards him, he will react in kind. It is a warning that if someone is going to start a fight, they should be prepared for a fight in return. The metaphor of throwing hedgehogs and porcupines is a method of saying that if someone is going to be aggressive, they ought to anticipate to get the same level of aggressiveness in return. This quote is a suggestion that if somebody is going to be hostile, they must be prepared for the consequences. It is a method of saying that if someone is going to begin a battle, they need to be prepared to deal with the repercussions of their actions.