
Originally Posted by
poopdeville
Crocodile can be cut as well, if he's wet. Enel can be cut as well, with a sharp, hard rubber knife, or glass (which, like rubber, is an insulator). Neither can "rebuild" themselves in that case. Indeed, both Enel and Crocodile bled after getting beaten by Luffy.
Luffy is SLIGHTLY weaker in that regard since any sharp object can cut him. But he is made of rubber, or else he couldn't do Second and Third Gear, which rely on his organs and bones being made of rubber.
Also, rubber trees. Though most rubbers are synthetic, there are many natural rubbers.