I've recently finished building a village in Far Harad, occupied by Vanilla villagers I relocated from the overworld using Elven Portals, and during that time, I had to deal with crocodiles quite frequently. It was then that I realised these mobs need an update.
First of all, crocodiles have 20 hitpoints, the same as a normal human NPC, in addition to possessing no armour points. This, of course, is far too low for a heavily scaled reptile several times the mass of a human. I propose that crocodiles be upgraded to have either 35 health and moderate (leather strength) armour points, or have 50 hitpoints with no armour (personally, I prefer the first option)
Then, there's their attack strength. Crocodiles, with one of the strongest bites of any extant animal, only deal a mere two hears of damage! This should be updated to at least five hearts, possibly more. At the moment, crocodiles are nothing more than a nuisance, if that.
Finally, there's the matter of their spawning. I propose that their spawning be adjusted to only sand blocks near water. That (if I'm correct in assuming sand doesn't generate underground) should stop them from spawning in caves, as well as infesting farms.
That's it for this suggestion. Let me know what you think!