Answer: nitpicker

AnswerCrossword Clue
NITPICKERFussbudget
NITPICKERFaultfinder extraordinaire
NITPICKEROverly critical one
NITPICKERFussy fellow
NITPICKERNiggler
NITPICKEROne overly concerned with details
NITPICKERHairsplitter
NITPICKERLice checker who's fussy?
nitpickerone who nitpicks (to fuss over petty details)