"They are lean and athirst!" he shrieked... "All the evil in the universe was concentrated in their lean, hungry bodies. Or had they bodies? I saw them only for a moment, I cannot be certain." —Frank Belknap Long, "The Hounds of Tindalos"
The Hounds of Tindalos dwell in the distant past of the earth, when normal life had not yet advanced past one-celled organisms. They are said to inhabit the angles of time, while other beings (such as humankind and all common life) descend from curves. The Hounds are thought to be immortal and are believed to lust after something in humankind and other normal life, and will follow victims through time and space to get it. Their appearance is unknown because no characters who meet them survive long enough to give a description. It is said that they have long, hollow tongues or proboscis to drain victims' body-fluids, and that they excrete a strange blue pus or ichor.
Though the Hounds are sometimes pictured as canine, probably because of the evocative name of the first story in which they appeared, it is not likely that they appear as such- the story states that the name "veils their foulness". Various pastiches suggest that the Hounds are more bat-like in appearance, like the byakhee, or may appear even worse. The name Hounds of Tindalos refers more to the creatures' habits than their appearance.
Because of their relationship with the angles of time, they can materialize through any corner if it is fairly sharp—120° or less. When a Hound is about to appear, it materializes first as smoke pouring from the corner, and finally the head emerges followed by the body. It is said that once a human becomes known to one of these creatures, a Hound of Tindalos will pursue the victim through anything to reach its quarry. A person risks attracting their attention by travelling through time.
The Hounds of Tindalos are among the monsters attacking Edward Carnby and Aline Cedrac in "Alone in the Dark : The New Nightmare", the fourth installment of the Alone in the Dark video game franchise. The game was published by Infogrames in 2001 on PlayStation, Dreamcast, PC and PlayStation2.
In the story Tindalos by John Ajvide Lindqvist, the main character is haunted by a being named Tindalos. It shares many attributes with the creatures in "The Hounds of Tindalos", and the main character reads the Frank Belknap Long story in-story, as a way of gaining an understanding of the chewing sound that haunts her.
The Hounds chase the time-travelers "Titus Crow" in Brian Lumley's "The Transition of Titus Crow" (book II of the Mythos Omnibus or Cthulhu Cycle Deities saga), and Henri-Laurent de Marigny in "Elysia" (book VI of the same series).
Shadow Hearts uses a very loose interpretation of one of the creatures as a boss. Tindalos, as it is referred to, is depicted as resembling the rotting corpse of a giant, skinned dog, and is of a very different origin from the Hounds.
In The Unspeakable Vault (Of Doom), a webcomic satirizing the Cthulhu Mythos beings, there is a lean, dog-like being known as "Tindaloo" which is capable of passing through other dimensions and sometimes acts as the "family dog" to the deities. He lives in a doghouse inspired by the works of Escher.
The hounds also appear in the Roger Zelazny novel The Changing Lands, attacking the main characters as the house they are in travels through time.
A hound of Tindalos appears in Michael Cisco's short story, The Firebrands of Torment in such a way as to suggest that the protagonist might actually be the offspring of one.
In the short story "Mongoose", by Sarah Monette and Elizabeth Bear, the Hounds are described as the apex predators of an extra-dimensional food chain that also includes the bug-like Toves and large-mouthed, eyeless Raths. The Hounds are referred to by the scientific name Pseudocanis tindalosi, which literally means "the false dog of Tindalos", but most of the characters call them "Bandersnatches" after a creature in Lewis Carroll's poem "Jabberwocky".
In Donald Tyson's Alhazred Author of the Necronomicon the character Sashi meets Alhazred on his wanderings, she resembles one of these hounds, although the spirits do not call themselves by that name. Sashi resides in Alhazred's body and becomes something akin to a spirit-lover.
The Hounds are referenced twice in Haiyore! Nyaruko-san. In one episode, Nyaruko offers to make Mahiro a hot dog using Hound of Tindalos meat; Mahiro angrily responds "Go bang your head on the angles of time!" In another episode, the corners of Hasuta's bedroom are shown to be covered with putty (presumably to proof his room against the Hounds); Mahiro asks why, but Hasuta refuses to explain, instead saying that he is better of not knowing the reason.
In Lawrence Santoro's Bram Stoker nominated novella, "God Screamed and Screamed, Then I Ate Him," the Hounds of Tindalos accompany Bunch, the Daughters of the Elachmani and the tiny, winged Jabachar into the deep caves near Bluffton to summon the great old one from the depths to be slaughtered by the "Ellman" twins. The story was worked into Santoro's novel, "Just North of Nowhere."
In Graham McNeill's Warhammer 40,000 novel Gods of Mars, the malevolent predator-constructs utilized by the primary antagonist Magos Telok were called Tindalosi. These ancient artificial intelligences were created for the sole purpose of hunting and killing specific targets, before they turned against their long-forgotten masters and were exiled. Magos Telok recovered several of them and repurposed them with forbidden technology to serve his own purposes.
Long, Frank Belknap. "The Hounds of Tindalos" (1929). In Tales of the Cthulhu Mythos (1st ed.), Random House, 1998. ISBN 0-345-42204-X.