This card just seems completely out of its element to me. "Nile crocodile", the Nile is a river, therefore it would be logical for this to be a water card. I get the Egyptian reference, but thats a pretty weak reference. Say "Nile" and I think of a river, not a desert.
The ability is just as out of place, why should it take water to bite something? Most other off-element abilities are logical as to why they are off element: Lava destroyer uses earth to make more lava, forest spirit grows with water, devourer burrows in the earth, parasite uses death to infect stuff, gargoyle solidifies with earth, graviton fire eater eats fire, the list goes on.
I would just make it a water card, with its current stats/cost, and make the ability cost either water, or maybe 2-3 random quanta.