Tulpas, a W-class monster that is exclusively summoned by casters, especially monk-types and Master Kaen, with several of Kaen’s appearing through the monk quest. They take on some of the properties of their caster, and leave no corpse.

The monk quest is very loot-sparse in terms of random items being generated on the floors of the levels (death drops are unaffected), because all the major players are either monks, without much in the way of worldly possessions, or elementals who don’t have any items.