That is the flyback transformer used to generate the high voltage charge in a laser printer.
The comparable circuits in a CRT-based television can remain hazardous for substantial time after power is removed, unless the tube capacitance is carefully drained by someone knowledgeable in the appropriate procedure.
I can't tell you off the top of my head what associated capacitance would be found in a laser printer or what voltage it would charge to, but until you know for certain, you probably don't want to be working on or disassembling the machine - if something is still charged the results could range from surprising through painful to truly hazardous, even when unplugged from the wall. Such hazards are not necessarily confined to televisions or large objects - in childhood I got a rather unique burn from discharging the capacitor in a small camera flash through my finger.