First: The mob have dropped maybe 15 Axes for me, but NO hammer. Might be rare, but seems to not drop any more.
Second: Don't corner the mob in his cubicle - if you do, he fights until death - if not - he deathflees at 20% (depends on level).
Third: As mentioned earlier - the spirit with a capital I spawns Abram (Incoherent, and not incoherent).
Fourth: If close call on spirit - do not engage it while Abram's up - he'll not fight to help spirit, but he'll heal the spirit.