cocky

conceited or arrogant, esp. in a bold or impudent way.

cranky

ill-tempered; irritable: he was bored and cranky after eight hours of working.

impudent

not showing due respect for another person; impertinent: he could have strangled this impudent upstart.

unprecedented

never done or known before: the government took the unprecedented step of releasing confidential correspondence.

capitalize

1 [ no obj. ] (capitalize on) take the chance to gain advantage from: an attempt by the opposition to capitalize on the government's embarrassment.

fanatic

a person filled with excessive and single-minded zeal, esp. for an extreme religious or political cause.