The thing about animals is that most of them have extremely keen senses of smell. Croc can smell them coming, even if he hadn't heard them stomping around like a lame bull.

That's a little uncharitable; perhaps he is blowing it out of proportion. Croc lays in wait along the bank, waiting patiently for the child to venture further. He growls, low in his throat; sounds like a pissed-off rattler. Despite doubts, he decides to speak.

It's not like Frisk has experience in FLEEing giant, angry monsters with sharp teeth-- wait.

"What're you doing down here all alone, runt?"