Tiefling - (TEEF-ling). A creature born of a human and a lower planar creature. Tieflings usually display some physical characteristic of their heritage such as small horns, a tail, different skin color, or the legs of a best such as a goat or bull. They are quarter breeds, the union of a half-fiend and a human since when a full blood fiend mates with a human the result is a Cambion or Alu-Fiend or similar half breed fiend.
Aasimar - (ACE-im-ah). A creature born of a human and a celestial of some kind such as an Archon or Deva. Usually much less physically marked than a tiefling an aasimar can be identified by silvery or golden skin or eyes, and are normally very beautiful.
Baatezu - (bay-ah-TET-soo). A race of fiends native to Baator (the Nine Hells), known on most Prime worlds as Devils.
Tanar'ri - (tan-AH-ree). A race of fiends native to the Abyss, known on most Prime worlds as Demons.
Manes - (MAYNZ). The least of the Tanar-ri (note that Manes is both singular and plural).
Rutterkin - (RUT-uh-kin). Grossly deformed lesser Tanar-ri.
Dretch - (DRETCH). Short, green, fat Tanar'ri with bloated bellies and droopy faces. They have long floppy ears. Only a step above Manes in the Tanar'ri food chain the Dretch travel in large packs attacking anything they think they can kill.
Cambion - (CAM-be-on). A Tanar'ri half breed, born of a Tanar'ri father and human mother. Rarely other races such as elves may give birth to Cambions.
Hezrou - (HETZ-row - the row rhymes with cow). Huge frog-like behemoths, the Hezrou marshall the Tanar'ri armies making sure everyone is ready when the army marches to battle.
Yugoloth - (YOO-go-loth). A race of fiends native to the Grey Waste and Gehenna. The Grey Waste is known as Hades on some Prime worlds.
Baernoloth - (BAIRN-o-loth). Ancient fiends of vast power, it is said they were the first fiends. They are said to have spawned the Yugoloths from the Grey Wastes, and legend claims they are responsible for the creation of the Tanar'ri and Baatezu as well.
Ultroloth - (ULL-tro-loth). The most powerful caste of Yugoloths, their power is feared across the planes.
Arcanaloth - (ar-KAR-na-loth or ar-KAIN-ah-loth). A type of Yugoloth distinguished by their jackal-like heads and affinity for magic. They are considered the "lore and contract keepers" of the Yugoloths.
Mezzoloth - (MEZZ-oh-loth). The most common and lowest caste of the true Yugoloths, Mezzoloths are stupid and incredibly brutal.
Githyanki - (gith-YANG-kee). Warrior race that lives on the Astral Plane.
Githzerai - (GITH-zeh-rye or gith-ZEHR-i). Race of beings native to the Plane of Limbo.
Bladeling - (BLADE -ling). Creatures native to the plane of Acheron, their skin is blue and metallic and covered in hundreds of thin metal and bone spikes that they can fire of in a burst from their chest.
Khaasta - (KASS-tah). A race of tribal lizard like humanoids native to the Outlands.
Dabus - (DAH-bus). A race of beings that are found only in Sigil. The communicate via illusory rebus' and are said to be the caretakers of Sigil (And perhaps it's original inhabitants).
Bariaur - (BAR-ee-or). A race of centaur like creatures that have the bodies of goats with human torsos and arms, native to several of the Upper planes.
Genasi - (JEN-ah-see). Similarly to tieflings, the genasi are plane-touched beings that half human and half elemental.
Asbravn - (AZ-brav-an)
Hluthvar - (huh-LUTH-var)
Berdusk - (BER-dusk)
Iriaebor - (irry-AY-bor)
Khin-Oin - (KIN-oyn) - The tower where the Oinoloth dwells (along with many thousands of Yugoloths).
Sigil - (SIG-ill hard 'g' or (more rarely), SID-jill). An outer planar city (some would say THE outer planar city).
River Ma'at - (MUH-AHT). A sluggish, wide river that flows from Torch to excelsior in the Outlands before evaporating in a vast salt plain. The river is dotted by many small villages, most of which are home to petitioners of the Egyptian god Thoth.
Baator - (bay-ah-TOR). A plane of evil and law, often called the Nine Hells on some Prime planes.
Avernus - (ah-VER-nus). First layer of Baator.
Oinos - (OY-noss). The first layer of the Grey Waste, usually referred to as the First Gloom.
Acheron - (AY-ker-on or ASH-er-on). A battle plane of Law tinged with evil.
Amon'Valura (Khorle) - (AY-mon val-OO-ra)(KORL) - the Staff of Knowledge.
Unagi - (OO-nar-gee or YOO-nar-gee. A hard 'g' in both cases).
Silvara - (sil-VAR-ah).
Shadow Flame and Jean DaGrey are pretty obvious!
Ixxizigut - (ix-e-ZIG-ut). The imp bound to Shadow Flames amulet.
Jergal - (JER-gull). The god who records the names of the dead, anticipating the end of all.
Selune - (seh-LOO-nee). Torilian goddess of the moon.
Lliira - (LEER-ah). Torilian goddess of happiness and festivals.
Ilmater - (ihl-MAY-tah). Torilian god of suffering and martyrdom.
Deneir - (den-EER). Torilian god of glyphs and images.
Oghma - (og-MAH). Torilian god of knowledge.
Heironeous - (air-OH-nee-us). Oeridian god of Chivalry, Justice, Honor, War, Daring, and Valor.
Oinoloth - (OY-no-loth). The titular ruler of the Yugoloths; it's a bit more complicated than that but hey, this is just a pronunciation guide!
Mydianchlarus - (mid-e-an-CLAR-us). A very powerful Ultroloth and the current Oinoloth.
Anthraxus - (an-THRAX-us). Previous Oinoloth, known as "the decayed".
Obermast - (oh-ber-MASST). Harper bard.
Astyaril - (AST-yair-ill). The high Priestess of the Altar of the Moon, temple to Selune in Iriaebor.
Shemeska - (sheh-MESS-kah). An Arcanaloth business woman with plenty of jink to go around.
Estavan - (es-teh-VARN). A high up in the Planar Trade Consortium.
Zulik Kor'Shek - (Zoo-lik Kor-SHEK). Githzerai trader working for the Planar Trade Consortium.
Ignatius Vallior - (ig-NAY-she-us VAL-e-or). A Black Monitor, member of the Readers of the Scrolls, a chapter house of the Black Cult of Ahm in Sigil.
Tulket nor Ahm - (TULL-ket nor ARM). Wizard and sage, author of the Black Scrolls of Ahm and other writings concerning the Abyss and the Tanar'ri
Nazh'Duk - (nazz-DOOK, the dook rhymes with book). The Githyanki Gish who bound Amon'Valura to the staff of knowledge.
Misercardiam - (MY-zuh-CAR-dee-am). A Night Hag who owns and runs the Alchemy shop in Hopeless.
Mealle the Just - (meal-lee). A tiefling who runs the weapon shop in Hopeless.
Vaimish Crasad - (VAY-mish cruh-SAHD). A paladin of the Oeridian god Heironeous and a member of the sect called the Order of the Planes Militant.