Note: This information was taken from TSR's original AD&D adventure, the Temple of Elemental Evil.
For the DM: The Master's chamber is lavishly furnished, with thick rugs, wall hangings, and soft chairs, couch, and cushions. Wines, liquors, and dishes of sweetmeats abound. A brazier continually burns, warming the place and sending a fragrant incense into the air. Silver serving pieces and goblets (worth 4, 000 gp for all) and an alabaster box filled with unguents (total value 800 gp) are in plain sight. Hidden in a cabinet is an exquisite piece of jewelry, made with matched fire opals (ten gems worth 1, 000 gp each) on a gold chain and settings with diamond chips (5, 000 gp). The New Master, Lareth, is described more fully below. He carries but 9 pp and one black opal (1, 000 gp). On his left arm is bound a phylactery of action, a clerical magical item which makes the wearer impervious to paralyzation of any sort, including all hold spells and spell-like powers.

Lareth will aid his guards' melee with his spells, keeping a defensive posture while commanding his troops' attacks. He will melee if necessary, and probably after using his spells. He wields a mace in his left hand (D 1-6, -2 "to hit" as secondary weapon) and a staff of striking in his right (staff + 3, D 4- 9, 20 charges; uses 1 per hit, or 2 for double damage, 3 for triple).

If seriously threatened, Lareth will offer all his non-magical treasures--jewelry, coins, and all else--as ransom for his life. If Lareth is slain, there will be cautious and discreet inquiries in Hommlet, as the servants of evil therein make every attempt to find out what happened. If any of Lareth's possessions turn up, the slayers are revealed. An assassin of 10th level who can speak the alignment language of the individuals, as well as those of major allies, will come to the village in 5-20 days to eliminate the offender(s). DM, handle this as you see fit. Jaroo and Terjon of Hommlet will certainly aid those attacked. If the assassin is killed, nothing further will be attempted.

Lareth: AC -1 (plate mail + 1); Level 5 Cleric;
hp 44; #AT 1; D 1-6 (mace) or 4-9
(or more, from staff of striking-, 20 charges remain);
SA spells (see below); SD immune to paralysis (phylactery of action); XP 770
S 18 W 18 D 17 C 16 Ch 18

First level: command, cure light wounds (x2), protection from good, sanctuary
Second level: hold person (x2), know alignment, resist fire, silence 15' radius
Third level: cause blindness, continual darkness

Lareth the Beautiful is the dark hope of chaotic evil--young, handsome, well endowed in abilities and aptitudes, thoroughly wicked, depraved, and capricious. Whomever harms Lareth had best not brag of it in the presence of one who will inform the Demoness Lolth!

Lareth has been sent to this area to rebuild a force of men and humanoid fighters to gather loot and restore the Temple of Elemental Evil to its former glory. He is but one of many so charged, of course, but is looked upon with special favor and expectation. He and his minions have been careful to raid far from this area, never nearer than three or four leagues, travelling on foot or riding in wagons of the traders from Hommlet. None of the victims are ever left alive to tell the tale, and mysterious disappearances are all that can be remarked upon. No trace of men, mounts, goods, wagons or draft animals is ever found.

Evil to the core, Lareth is cunning. If a situation appears in doubt, he uses bribery and honeyed words to sway the balance to his favor. He is not adverse to gaining new recruits of all sorts, and will gladly accept adventurers into the ranks (though he will test and try them continually). Those who arouse suspicion will be quietly murdered in their sleep. Those with too much promise will be likewise dealt with, for Lareth wants no potential usurpers or threats to his domination.