;Delapore :The narrator. His first name is not mentioned. He changes the spelling of his name back to the ancestral "De la Poer" after moving to England. The title of
Baron De la Poer actually exists in the
Peerage of Ireland, and the spelling is indeed derived from
le Poer, Anglo-Norman for "the Poor"; it is of some interest in peerage law. ;Alfred Delapore :The narrator's son, born c. 1894. He goes to England as an aviation officer during World War I, where he hears stories about his ancestors for the first time. He is badly wounded in 1918, surviving for two more years as a "maimed invalid". ;Edward Norrys :A captain in the Royal Flying Corps during World War I, Edward Norrys befriends Alfred, and amuses him by telling him the "peasant superstitions" surrounding his family's history, which Norrys picked up in his native Anchester. He is described as "a plump, amiable young man". He and Delapore are the ones who initially find the altar that leads to the grotto beneath the priory, and is ultimately killed and partially eaten by the now-insane Delapore, who is revealed to have hated him due to him having lived while Alfred died. It is also implied that Norrys is the model for the "animals" that Delapore sees being herded by the swineherd in his dreams. ;The swineherd :A nameless being (heavily implied to represent Delapore himself) that Delapore sees in his dreams, tending to his unseen herd in a twilit grotto. It is his dreams of the swineherd that drive Delapore to investigate the city beneath the priory, as it matches the grotto that he sees in his dreams. ;Sir William Brinton :One of the "eminent authorities" that accompanies Delapore's expedition beneath Exham Priory, Sir William Brinton is an archaeologist "whose excavations in the
Troad excited most of the world in their day." It is Brinton who figures out how to move the counter-weighted altar that leads to the caverns, and who noted that the hewn walls must have been chiseled "from beneath". He is the only member of the expedition who retains his composure, when they discover the horrors below the priory. ;Dr. Trask :Another eminent authority, Trask is an anthropologist who is "baffled" by the "degraded mixture" he finds in the skulls below Exham Priory—"mostly lower than the Piltdown Man in the scale of evolution, but in every case definitely human". The
Piltdown Man, skeletal remains of a supposedly prehistoric humanoid, was discovered in 1912; it was not known to be a hoax until 1953, thirty years after the publication of "The Rats in the Walls". Trask determines that "some of the skeleton things must have descended as quadrupeds through the last twenty or more generations". ;Thornton :The expedition's "psychic investigator", Thornton faints twice when confronted with the nightmarish relics below Exham Priory, and ends up committed to the
Hanwell insane asylum with Delapore, though they are prevented from speaking to one another. Hanwell was an actual asylum, which Lovecraft probably read of in
Lord Dunsany's "The Coronation of Mr. Thomas Shap" in
The Book of Wonder (1912). ;Gilbert De la Poer :The first Baron of Exham, granted title to Exham Priory by
Henry III in 1261. There is "no evil report" connected to the family name before this point, but within 50 years, a chronicle is referring to an unnamed De la Poer as "cursed of God". ;Lady Margaret Trevor :Lady Margaret Trevor of
Cornwall married Godfrey De la Poer, second son of the fifth Baron of Exham, probably in the 14th or 15th centuries. Her description in the story vaguely resembles that of the historical figure Countess Bathory. Such was her enthusiasm for the Exham cult, that she "became a favorite bane of children all over the countryside, and the daemon heroine of a particularly horrible old ballad not yet extinct near the
Welsh border". ;Lady Mary De la Poer :After marrying the Earl of Shrewsfield (a title invented by Lovecraft), she was killed by her new husband and mother-in-law. When they explained their reasons to the priest they confessed to, he "absolved and blessed" them for their deed. ;Walter De la Poer :The eleventh Baron of Exham, he killed all the other members of his family with the help of four servants, about two weeks after making a "shocking discovery", and then fled to
Virginia, probably in the 17th century. He is the ancestor of the American Delapores and is the only De la Poer not hated by the people of Anchester, who revere him as a hero. He was remembered as "a shy, gentle youth", and later as "harassed and apprehensive"; Francis Harley of Bellview, "another gentleman-adventurer", regarded him as "a man of unexampled justice, honor, and delicacy." ;Randolph Delapore :Randolph Delapore of Carfax, the Delapores' estate on the
James River in
Virginia, "went among the Negros and became a
voodoo priest, after he returned from the
Mexican War". He is a cousin of the narrator, who regards him as "the one known scandal of my immediate forebears", and who sees this race-mixing life as "unpleasantly reminiscent" of the "monstrous habits" of the ancestral De la Poers. Carfax Abbey is the name of Count Dracula's British outpost in the novel
Dracula—a setting that has been suggested as an inspiration for Exham Priory. ;The Cat :A cat owned by the narrator, originally named "Nigger-Man", but changed to "Black Tom" when the story was reprinted in
Zest magazine in the 1950s. He could detect the spectral rats. == Inspiration ==