This is the last in series of three articles. Like you probably got from the title, it's a list of characters. :) But beware! It include SPOILERS!

Characters that actualy appear:
(the categories humans, dwarfs, elves, urgals and dragons are often just assumpted)
-Humans:
Angela - witch and herbalist
Albreich and Baldor - Horst's sons
Birgit - Quimby's wife
Calitha - woman from Carvahall
Carn - Varden spellcaster
Delwin - man from Carvahall
Darmmen - man from Carvahall
Denwood - Galbytorix's soldier
Edric - Varden captain
Elain - Horst's wife
Elva - witch-child; result of Eragon's gone wrong blessing
Fadawar - chief of a nomadic tribe; Nasuada's cousin
Farica - Nasuada's handmaid
Felda - Byrd's wife
Fisk - man from Carvahall
Fletcher - man of Varden
Fredric - Varden's weapon master
Galbatorix - mad king of Alagaësia (appears only while speaking through Murtagh)
Garven - Varden man, captain of Nasuada's guards
Gedric - man from Carvahall
Greta - Elva's caretaker
Graytooth - middle-aged horseman
Halmer - one of Redbeard's man
Helen - Jeod's wife
Herald - Varden man who fought together with Roran
Horst - blacksmith from Carvahall
Irwin - prime minister of Surda
Isold - woman from Carvahall
Jarsha - message boy
Jeod - ally to the Varden; Brom's friend
Jörmundur - Nasuada's right hand
Katrina - Roran's wife
Kiselt - man from Carvahall
Lang - Varden veteran
Lenna - woman from Carvahall
Loften - Varden man
Lady Lorana - ruler of Feinster, sworn loyalty to Galbatorix
Loring - man from Carvahall
Mandel - man from Carvahall
Martland Redbeard - Varden captain
Morn - man from Carvhall
Murtagh - Morzan's and Selena's son, Eragon's half brother; a Rider; Galbatorix's right hand; unlike in the previous books, his hair is black
Naako and Ramusewa - members of Inapashunna tribe
Nasuada - queen of Varden
Nolfavrell - Quimby's son
Orrin - king of Surda
Quath - member of Varden
Roran - Eragon's cousin
Sabrae and Umérth - members of council of members
Sand - Edric's familiar
Sloan - butcher; Katrina's father
Tara - Morn's wife
Trianna - leader of Du Vrangr Gata
Ulhart - Martland Redbeard's right hand

-Elves:
Alanna and Dusan - elf children from Ellesméra
Arya - princess and diplomat
Blödhgarm - one of the elves that came to Varden
Lord Däethedr - an elf of importance
Lord Fionir - owner of Támerlein, green Rider sword
Gilderian - guard of Ellesméra
Islanzadí - queen of elves; Arya's mother
Linnëa - an elf woman that turned herself into part of Menoa Tree
Rhunön - an elf blacksmith

-Dwarfs:
Farn - Orik's messenger
Freowin - grimstborith of Durgrimst Gedthrall
Gáldhiem - grimstborth of Durgrimst Feldunost
Gannel - grimstborth of Durgrimst Quan
Glumra - Kvîstor's mother
Hadfala - grimstborth of Durgrimst Ebordac
Havard - grimstborith od Durgrimst Fanghur
Hreidamar - grimstborith of Durgrimst Urzhad
Hundfast - Eragon's translator
Hvedra - Orik's wife
Íorunn - grimstborith of Durgrims Vrenshrrgn
Mannndrâth - grimstborth of Durgrimst Ledwonnu
Nado - grimstborth of Durgrimst Knurlcarathn
Nerheim - temporal commander of dwarf troops
Orik - grimstboth of Durgimst Ingeitum; king of dwarfs; Eragon's friend
Skeg - dwarf, responsible for reassembling the star saphire
Thordris - grimstborth of Durgrimst Nagra
Thrand - one of Eragon's dwarf guards
Undin - grimstborith of Durgrimst Ragni Hefthyn
Vermund - grimstborth of Az Swelden rak Anhuin

-Urgals:
Dazhgra - an Urgal spellcaster
Garzhvog - Kull chief
Yarbog - an Urgal that challenged Roran

-Dragons:
Glaedr - Oromis's dragon
Saphira - Eragon's dragon; blue
Thorn - Murtagh's dragon; red with crimson eyes

-Other/Unknown:
Eragon - boy of 16; a Rider
Maud - werecat from Ellesméra
Solembum - werecat
Tanga - an old hermit

Characters that are only mentioned:
-Humans:
Braethan - Galbatorix's soldier
Gertrude - healer from Carvahall
Hargrove - one-leged man who tought Nasuada how to shield her mind
Helfring - man that stole Saphira's egg from Galbatorix
Marcus Tábor - governor of Dras-Leona
Lord Risthart - works for Empire
Lord Tarrant - lord in Ceunon
Welmar and Lindel - two of Martland's men

-Elves:
Liotha - Blödhgarm's cousin

-Dwarfs:
Shrrgnien - guard

-Urgals:
Skgahgrezh - Garzhvog's brother

-Dragons:
Shruikan - Galbatorix's second dragon; black

Characters that are die before the end of the book (bold) and characters that died before this book begins (italics):
-Humans:
Ajihad - king of Varden; killd by Urgals
Barden - spellcaster
Brom - a Rider; killed by Ra'zacs
Byrd - man from Carvahall; killed by Ra'zacs
Ferth- one of Redbeard's man; killed by Galbatorix's soldiers
Garrow - Eragon's uncle, Roran's father, Selena's brother
Ismira - Sloan's late wife
Langward - soldier
Marian - Garrow's wife; Roran's mother
Morzan - first and last of the Forsworn; Murtagh's father; killed by Brom
Othmund - Varden man that killed three Urgals; hanged on Nasuada's order
Parr, Hida, Elmund, Kelby - villagers from Carvahall; killed by Galbatorix's soldiers
Quimby - man from Carvahall; killed by Ra'zacs
Sefon - one of Nasuada's swordsman
Selena - Black Hand of Morzan; Eragon's and Murtagh's mother
Torkenbrand - man killed by Murtagh
Twins - two bald magicians; killed by Roran

-Elves:
Arva - an elf Rider, died during the Fall of the Riders
Glenwing and Fäolin - elves that traveled with Arya
Naudra - Fionir's mate, brother of Arva
Oromis - an elf Rider; Eragon's teacher; killed by Murtagh

-Dwarfs:
Bauden - Glumra's late husband
Hrothgar - dwarf king; killed by Murthagh
Kvîstor - guard

-Dragons:
Iormungr and Vervada - Saphira's parents
Jarnunvösk - Galbatorix's first dragon; killed by Urgals
Saphira - Brom's dragon

-Other/Unknown:
Durza - a Shade; killed by Eragon
Heslant the Monk - author of Domina abr Wyrda
Kialandí and Formora - two of the Forsworn; probably humans
Ra'zacs - one killed by Eragon and other by Roran
Varaug - a Shade; killed by Arya

Characters from stories; historical fiures:
Deynar - one of previous leaders of Varden
Durak Ornthrond - dwarf that made the star saphire
Eragon - the first Rider
Gerand - warrior from Brom's story
Guntera - dwarf god
Hvalmar - dwarf that started the excavation of forest of stone
Kaga - dwarf king, killed by novice swordsman
Korgan - first dwarf king
Maghara, Hegraz, Rahna - Urgralgra from legends
Ring Giver - Orrin's ancestor
Tarmunora - queen of elves
Weldon - one of previous leaders of Varden

Note: It's very likely I've missed a few characters and you are welcome to mention it in the comments if you find some.