stickler (n.)

• arrogator
• ass
• autocrat
• bigot
• bullethead
• caesar
• commissar
• czar
• despot
• dictator
• diehard
• disciplinarian
• dogmatist
• donkey
• driver
• duce
• fanatic
• martinet
• maverick
• mule
• nitpicker
• oligarch
• oppressor
• perfectionist
• pharaoh
• positivist
• purist
• tyrant
• usurper
• warlord