What is Huck surprised about that Jim does?

Jim is even more superstitious than Huck. Jim constantly surprises Huck with the things he says and does. Consider the following:

"Jim said the witches bewitched him and put him in a trance, and rode him all over the State, and then set him under the trees again, and hung his hat on a limb to show who done it."

"Miss Watson's nigger, Jim, had a hair-ball as big as your fist, which had been took out of the fourth stomach of an ox, and he used to do magic with it. He said there was a spirit inside of it, and it knowed everything."