Anyone who has read Huck Finn please help!?

This shows that Huck and Jim are superstitious, which is a central theme of the book. It also shows that even though Huck still looks down on Jim, enough to play a mean prank, he is starting to feel bad for Jim, as shown when he feels bad after Jim gets bit by the snake. As a result, this event is a milestone in Huck's moral development througout the book.