Can you name me some land animals that can kill a crocodile?

An elephant could trample one to death without too much difficulty, and a hippo could likely kill one with its devastating bite (if you consider a hippo a land mammal, that is). A rhino could possibly kill one by spearing it with its horn. Lions are known to kill Nile crocodiles on occasion, and tigers to kill mugger crocodiles, so it's possible they could kill a saltie if they came into contact with it, but I wouldn't say they could do so 'with ease'. A human with the right weapon can kill just about anything, if that counts.