Lucifer

& Lucifer
Difficulty	49
Attacks	Weapon 2d8 armor shredding, Weapon 2d8 armor shredding, Weapon 2d8 physical, Weapon 2d8 physical, Claw 2d8 Quest Artifact theft, Gaze attack 8d8 random gaze type

& Lucifer
Difficulty	49
Attacks	Weapon 2d8 armor shredding, Weapon 2d8 armor shredding, Weapon 2d8 physical, Weapon 2d8 physical, Claw 2d8 Quest Artifact theft, Gaze attack 8d8 random gaze type
Base level	39
Base experience	1913
Speed	19
Base AC	-13
Base MR	99
Alignment	10 (lawful)
Frequency (by normal means)	0 (Not randomly generated)
Genocidable	No
Weight	2000
Nutritional value	0
Size	large
Resistances	fire, cold, sleep, shock, poison, petrification
Resistances conveyed	sleep
Lucifer: can survive underwater. does not breathe. has a head, a couple of arms, and a torso. has a thick hide. is poisonous to eat. does not eat. (*) is not a valid polymorphable form. is male. is normally generated hostile. is strong. can pick up weapons and food. has infravision. never leaves a corpse. gives out light. may turn against you when tame. cannot be tamed.

Lucifer and Apollylon were both in dnethack until a recent(ish) revision. They are still in the code, however. Lucifer would be generated on Astral if you killed Apollylon.