Das ist The Darkness Beneath, Level 1: The Upper Caves, by Hackman, with Calithena and David Bowman, aus Fight On! Magazine Vol 2.
7-8. These two caves serve as the home of the Leprechaun Hamly and his Halfling minions. Both of these caves have a profusion of stalactites and stalagmites. If the Leprechaun is aware that a group is approaching, he will use his illusion ability to make the stalactites appear to be large black mushrooms. The Halflings will hide throughout the cavern and attempt to use their slings as long as possible. Meanwhile, Hamly will become invisible and transform any weapons he sees wielded. Alternatively, Hamly might just use invisibility and ventriloquism to make fun of the group while he and/or the silent, sneaky Halflings pick their pockets. Hamly can levitate as well, so he could steal something and levitate up. If defeated Hamly and the others will surrender, offer to scout and find the party gold, and so on, but will betray them at first opportunity. The northeast corner of 8 contains 10 cots and small trunks used by the Halflings for storage. Each Halfling trunk contains clothing, foodstuffs, 2d100 silver coins, and 1d8 platinum coins; one has a treasure map secreted away as well. There is a fountain of spring water in the area. There is a fire pit as well and if a group digs under this pit they will find a large iron trunk a few feet down containing Hamly’s treasure hoard. The trunk is locked and trapped with a poison needle in the lock (save or die within 1 hour). The chest contains 1000 gold coins, 2000 silver coins, 25 platinum coins, 3 silver armbands worth 75 gold each, a potion of Flying, a potion of Heroic Fighting that lets any character drinking it fight as three levels higher for ten minutes or so (get extra hp, better attacks and saves, etc.), and Illuminator, a +1 sword. Illuminator is a lawful blade with Intelligence and Egotism 8 and communicates empathically. It can detect evil and gems and any chaotic foe hit by it must save vs. paralysis. The blade’s mission is to expose corruption among nobility, and will withhold its help from players who don’t work to do so after a while. Halflings: LVL 1, DC 6, slings and swords and leather, excellent stealth/ambush/thievery abilities. Hamly: LVL 1, DC 8, HTK 5. Spells cast on Hamly fail 80% of the time. As desired, he can make himself invisible, transform any weapon-sized or smaller, non-living, non-magical item into any other, create illusions, or use ventriloquism. He also knows magic and can cast spells as a 3 rd level Mage: Slumber, Charm, Light, and Levitate. These spells plus See Invisible are all in his spellbooks, also in the trunk.