What would you call someone who easily gets mad over little things and feels that he is better than others?

Impossible to say: Many possibilities exist with someone who responds this way -- all the way from personality characteristic to psychopathology. Possibilities include alcoholics -- who often act as if normal rules don't apply to them, & are critical of others too. Hypomania; narcissistic, borderline, antisocial character disorders; general perfectionism, compulsiveness; some anxiety disorders; list goes on.