Particularly malevolent demons, the class D have the upper body of an ape and the cloven-hoofed lower body of a boar. They have rather small feathered wings as well, which seem undersized compared to their corpulent bodies. Unlike class A to C demons, these are immune to normal arms and must be attacked with magical weapons. Like other demonkind, they are able to cause darkness at will (10-ft radius). Their other abilities, which they can use at will, one at a time, are improved phantasmal force (as the 2nd level illusionist spell), fear (as the 4th level magic user spell), levitate (as the 2nd level magic user spell), detect magic (as the 1st level magic user spell), comprehend languages (as the 1st level magic user spell), dispel magic (as the 3rd level magic user spell), polymorph self (as the 4th level magic user spell), telekinesis (as the 5th level magic user spell, up to 500 lbs), project image (as the 6th level magic user spell), use a symbol of fear or discord (as the 8th level magic user spell), and gate (as the 9th level magic user spell) another class A to D demon (random class, 60% chance of success).

Certain class D demons have their own secret names, which makes it 90% certain they will answer a summons if it is spoken. Conjurers should be prepared to make impressive promises of treasure, magical items or living sacrifices when summoning a class D demon, especially by name. It should also be remembered that these demons particularly enjoy feasting on human blood and meat.