What kind of man was Mr. Plummer?

From the text:

The overseer's name was Plummer. Mr. Plummer was a miserable drunkard, a profane swearer, and a savage monster. He always went armed with a cowskin and a heavy cudgel. I have known him to cut and slash the women's heads so horribly, that even master would be enraged at his cruelty, and would threaten to whip him if he did not mind himself.