The Hounds of Tindalos are fictional creatures created by Frank Belknap Long and later incorporated into the Cthulhu Mythos when it was codified by August Derleth.

[1] They first appeared in Long's short story "The Hounds of Tindalos", first published in the March 1929 issue of Weird Tales.

In Frank Belknap Long's original story, which deals with the main character experimenting in time travel with the help of psychedelic drugs and esoteric artifacts, the Hounds are said to inhabit the angles of time, while other beings (such as humankind and all common life) descend from curves.

It is said that they have long, hollow tongues or proboscises to drain victims' body-fluids, and that they excrete a strange blue pus or ichor.

When a Hound is about to manifest, it materializes first as smoke pouring from the corner, and finally the head emerges followed by the body.