I've been impressed with the black mamba this year. It's been a breakout season for it. However I don't think it's got enough to beat the croc which has a ridiculously impressive list of attributes, both defensive and offensive. The croc is natures own elite S.A.S. I think the hippo could find itself in real trouble here and this could be its last hurrah as a serious player.
But again, you're going by the definition that something mega powerful IS hard. Which isn't all there is to it, as a huge bloke beating up a little bloke ISN'T hard. An Orca EATING a Honey Badger WOULDN'T be hard.
The Honey Badger's fans make the point that it does all the things it does, while basically being a lovable furry little shit. That's WHY it's hard.