Just read this on wiki...
The skin is also tough enough to resist several machete blows. The only sure way of killing them quickly is through a blow to the skull with a club or a shot to the head with a powerful rifle, as their skin is almost immune to arrows and spears.
Why on God's green earth would you want to kill that fucker? A cobra tried to kill him, and he just came back from the dead hungrier.
No, the only solution is to genetically engineer them to be as big as a tank. Then, we put saddles and rocket launchers on them, and we ride forth to crush all of our enemies across the planet. Al Qaeda, North Korea, Russia, France, all of them. No one could fuck with America then.