The barbed devil is flagged to only appear in Gehennom, but no lawful creatures can be randomly generated there; thus, they are effectively never randomly generated. This trait also occurs with horned devils and the erinys.
Barbed devils may be created in groups wherever they DO appear, and are valid forms for a polymorph trap, which may result in them appearing much earlier in the main dungeon. They are also eligible for gating by other major demons.
The barbed devil's damage is unimpressive, and even in groups they are not much threat to a player skilled in dealing with demons or multiple opponents.
These devils lack any real special abilities, though they
are quite difficult to kill.