[Edi]

Crocs and gators have nothing on the hippo. Even big crocs will give way because a hippo will generally kick their tail. A large hippo can weigh over two tons, so they can just trample a croc or a gator, or failing that, those teeth would really hurt. Hippos kill more people every year than crocs do and they will easily reduce a boat to a collection of matchsticks, toothpicks and unidentifiable splinters.

I would also note that a ten-foot python is not much ofa contest for a big gator or croc, but toss in a 20-footer or bigger one and it starts looking a lot different all of a sudden. For one, a lot more squeezing power, a snake that size is far stronger than a 10-foot one (which is quite capable of killing a human). Anacondas kill alligators and eat them, though once a gator gets big enough, it's no longer a viable meal.

But an escaped household snake against a wild croc or gator? Bleh. No contest.