What are the character traits for Mr Sir in Holes?

Mr. Sir in "Holes" is characterized by his tough and abrasive demeanor, often displaying a harsh and authoritarian attitude towards the boys at Camp Green Lake. He is also depicted as cruel and vindictive, taking pleasure in exerting power over the campers. Despite his rough exterior, he shows some signs of insecurity and desperation, particularly regarding his past failures. Overall, his character embodies a blend of intimidation and vulnerability.