Dark Knight: If you have a master necromancer, a semi-willing spirit, and a good suit of plate armor, you can put together a Dark Knight. Unlike Zeoreimers, these undead are somewhat articulate, and highly competent melee combatants. They also don't eat, sleep drink, party, get distracted by pretty girls, or otherwise get distracted from their duty at guarding someone.
Dark Knight Commander: Similar to a Dark Knight, except you need an adept class necromancer, and a completely willing spirit to produce one. Rare, even in House Nogrog territory, they possess all the fundamental and exotic combat skills they had in life, plus a host of necromantic energy stunts.
Deer, Blood-Spotted: A smaller (50-60 pound) species of deer, resembling the Indian chital, except the spots are reddish. Blood-spotted deer can be found over much of the northern continent between the Ebon Gulf and the Atan Shan mountains, and west of the Great EastFyre desert. These deer form herds of as many as fifty, and are opportunistic omnivores, to the degree that when facing a single or small group of predators, the herd will turn and attack rather than flee. The antler tips of blood-spotted deer secrete the same anti-coagulant substance found in stirge beaks.
Deer, Crystal: A forest herbivore the size of a moose, whose antlers are made of magical crystal. The colors of the crystals will give you an idea which elemental magics the deer can channel, and they rarely match. Not for novice adventurers. Major magic schools would sell the souls of their minor faculty to get the loot from one.
Deidarabotchi: A deer-like monster with a human face, native to the untamed forests of the Yamato Empire. Deidarabotchi can walk on water, apparently teleport if unobserved by people, and have an utterly alien set of motivations. If they encounter a person at night, they will cause that person to instantly die, collect their soul, and flee the scene. The following night, the deidarabotchi will attempt to implant that soul into some other corpse, thus raising it from the dead (and confusing the victim greatly, frequently unto mandess). Countless stories exist about the victim's loved ones trying to track down the creature on the second night and get the soul put back into the right body.
Demon: Supernatural creatures from the Darkness. Near infinite range of appearances and abilities, but do have several traits in common: vulnerability to sun and Holy(Jewel) light, malevolent, and cannot maintain a physical presence in the world without continuously expending personal energy. Possessing warlocks is their usual modus operandi for getting around most of these limitations.
Demon Bag, Carnivorous: The classic AD&D “Bag of Devouring”. Something went horribly wrong when this bag was enchanted, and it now connects, one-way, to the Darkness. Bags connected to particularly clever demons can fly around by air suction.
Devils: Supernatural creatures from the Darkness. More powerful and organized than demons, devils either will not or can not contract with warlocks or possess mortal beings. Usually make short appearances fueled by willing adherents, provide gifts and instructions, then retreat to the Darkness to watch the fun.
Dispossessed: Any warlock completely taken over by their patron demon, but not part of the Youkai cabal running Yamato into the ground. As a rule, dispossessed don't work well with one another, and most of the old ones are trying to live lives of off-camera indolence. The go-getters usually find themselves hunted down by the clergy, divine champions, enthusiastic adventurers, or worse, the Order of Shoushou Knights.
Dog, Wild: Feral descendants of domestic dogs. Survival of the fittest and unregulated breeding usually results in packs of animals about the size of a German Shepherd. Eventually get wiped out or absorbed by the local wolf packs.
Donkeys/Mule: Smaller than horses, but possessed of a few more brains and a heartier digestion. While they can be ridden, they do not make good war mounts.
Doomfold Dungeon: A living underground complex that just appears one day and can spawn an interior ecology of monsters, indefinitely. No one knows where they come from, but everyone agrees it is best to go in and kill the “core” while they are young: the older they get, the deeper they go, and the scarier the monsters they can create. There are several in each of the great empires at any given time, including one the Asterian Gladiator's Guild claims to have domesticated.
Dragon, Lesser: For very tenuous definitions of “lesser”. Powerful and cunning six-limbed flying reptiles. The appearance of one is a matter of national concern, for their thought processes and goals are rarely understood by mere mortals.
Dragon, True: Immense six-limbed reptiles of great power and intelligence. Generally treated as in the same category as the non-Jewelborn divine beings, we are discussing Tolkien or Lodoss dragons, not their pale, AD&D shadows. Hardly ever encountered in the Imperial Era, it is rumored they walk among us as mortals, or slumber deeply in hidden lairs. Several are documented to have been slain in the Degenerate Era.
Drake: Like wyverns, another four-limbed breed of lesser dragon. Unlike wyverns, drakes have four legs and cannot fly. Usually range between two and twenty tons, drakes can be found in nearly any environment, and frequently possess an elemental breath weapon. Drakes are usually non-sentient, and most of the talking ones are badly socialized at best. All the empires keep a couple around as weapons of war, and the Empire of the Fang has an entire division they use as mobile artillery.
Dracopotomus: Just what it says on the label. The warriors of Hazad aren't impressed by your northern, fully reptilian, drakes.
Druggavar: black goats the size of light horses with massive curved horns and glowing red eyes. These natively Evil creatures can be found throughout the northern territories, including Yamato. They are infused with elemental Mind magic, allowing them to paralyze or drive off victims with Fear, and are intensely territorial. Druggavar only appear at night, apparently spending the day in another (Astral) plane.
Duner: a peculiar beast from the Southern Isles and Hazad Caliphate. A six foot across, flattish, six-legged land tortoise, they are good at stable travel across loose sand, and will eat nearly anything. (Also are tasty, and keep well) Young duners are used to grant the well-to-do elderly mobility.