Huck discusses some superstitions. What are these and what might the point of including these be?

Huck is a product of his surroundings. Although aware of religion, he prefers the superstitions of the slave and marginalized population. Huck's domestication , and subsequent visits to church, with the widow Douglas doesn't come until later in his youth. Huck much prefers the mystery and colour of superstition. Check out this quote about the spider,

"Pretty soon a spider went crawling up my shoulder, and I flipped it off and it lit in the candle; and before I could budge it was all shriveled up. I didn't need anybody to tell me that that was an awful bad sign and would fetch me some bad luck, so I was scared and most shook the clothes off of me. I got up and turned around in my tracks three times and crossed my breast every time; and then I tied up a little lock of my hair with a thread to keep witches away. But I hadn't no confidence. You do that when you've lost a horseshoe that you've found, instead of nailing it up over the door, but I hadn't ever heard anybody say it was any way to keep off bad luck when you'd killed a spider."

Huck lives for imagination and adventure. Organized religion is stifling to Huck. Jim, the escaped slave, even confounds Huck with his hybrid of Christian stories mixed with African lore. Although Huck says he is bewildered by such tales, we can see that he incorporates bits and pieces of them into his imagination and even belief system.