What is Tom's treatment of the skull he finds with the tomahawk buried in it, and how does this reinforce his characterization?

Tom Walker is initially depicted as a miserly fellow, who continually argues and fights with his pugnacious, termagant wife. Tom Walker is also a callous, insensitive man, who has a sorrowful life on a forlorn homestead. When Tom stops to rest at an ominous region in the swamp on his shortcut home, he relaxes against the trunk of a fallen hemlock and begins to turn up the soil with his staff. Tom Walker accidentally ends up unearthing a buried cloven skull with an Indian tomahawk lodged into the side of it. After looking at the skull, Tom says, "Humph!" and gives it a kick, which immediately grabs the attention of Old Scratch, who tells him to leave the skull alone. Tom's rough treatment of the skull highlights his insensitive personality and propensity for violence. Tom Walker is further characterized as a disrespectful, tactless man with absolutely no concern for others.

When Tom finds the skull buried in the ground, his reaction is to kick it so as to remove the dirt. This action reinforces Tom's characterization in a couple of ways. Firstly, his violent reaction to the skull matches his fiery temperament. As we learn from the text, Tom is not an easy-going kind of person. He is constantly arguing with his wife, arguments which are described as being "bitter."
In addition, by removing the dirt to closer inspect the skull, Tom is presented as being self-interested and always on the lookout for material gain. We see lots of examples of this characterization in the text. His deal with the devil, for example, in which Tom agrees to become a moneylender in return for the lost treasure, proves how materialistic and greedy Tom is. His sole interest in life is increasing his personal wealth and status, a character trait which is first shown in his treatment of the skull.