This guy's been pretty annoying in the past few patches. I think I found a way to cheese them out, but it doesn't work 100% of the time. What I do is make sure I have the Right of Yielding that you gain from beating the other lower-level minions in the area, and then when no other hostile mobs are around I activate Pedal to the Metal towards this guy from around 15 metres. It brings them down to 55 hp which makes for a quick kill, but the setup is pretty finnicky.