You can see if this is around with the "events" command. So far it has always been in "Northern Fantasy Hills" which is basically around the road between the "road" portal and "wforest" portal in fantasy. It seems especially likely to show up to the west of the n/s portion of that road, but ymmv.
Scaler 117: A robotic lion [slashing antimagic berzerking] (7153043)
Scaler 42: A demon soldier [slashing regenerating ethereal] (69389)