As there are no trees at hand, this must necessarily be a crocodile.

Seldom can the best hand at stalking then get within eighty yards of him before he lifts his scaly head, and, listening for a second, plunges off the bank.
I have been contradicted in stating that a ball will penetrate their scales.

It is absurd, however, to hold the opinion that the scales will turn a ball--that is to say, stop the ball (as we know that a common twig will of course turn it from its direction, if struck obliquely).
The scales of a crocodile are formed of bone exquisitely jointed together like the sections of a skull; these are covered externally with a horny skin, forming, no doubt, an excellent defensive armor, about an inch in thickness; but the idea of their being impenetrable to a ball, if struck fair, is a great fallacy.

People may perhaps complain because a pea rifle with a mere pinch of powder may be inefficient, but a common No.

16 fowling-piece, with two drachms of powder, will penetrate any crocodile that was ever hatched.
Among the most harmless kinds are those which inhabit the salt lakes in the south of Ceylon.