This is another take on this creature, bearing much differnece in comparison to two previous ones. I have completely abandoned the idea with two heads on each body end, for the time in which they noticed the presence of time-traveller was too long for that to be likely. I still however stick firmly to the concept of "Spider-hounds" that stalk the webs/angles of time in search of unwary travellers.
I like Hounds very much for there is so little we know of them, yet I have based this appearance striclty on the infromation takien from the story.
1. "Angles of Time", the environment they are said to live in. I picture it as a giant web-liek structure, in which hound acts like a giant spider. Instead of giving it spider like looks, however, I made it's body composed of angular structures, likely reminding the rest of their reality.
2. "They have no bodies", The character wasn't sure whether the creatures are corporeal or not... I reflected that in their bodies turning in to smoke (That was later associated with their coming) here and there, making it somewhat etheral looking
3. Smoke, Tongues, blue slime. - As mentioned before, the creatures were appearing with a lot of smoke, and mentioned to use their tongues to attack (Victim was found decapitated and blood-sucked). To reflect it I gave it a set of appendages sticking out of the head, some of fhich could be used like saw, and one being clearly sucker-like. I imagine these creatures kind of "melt" on contact points, thus the smoke and blue liquid/slime they are associated with. Finally I gave it eyes, too. If the liquid is blue, it's likely that colours and dyes are somewhat present in their world, and thus eyes are understandable.
I do not follow the classic dog-like appearance of these.. I am convinced that that name is a reference to their tracking abilities, rather then looks (they don't have anything to do with dogs anyway
I wrote a lot but hey, there is more of my own vision here, than in other works so I'd like everyone to understand"Beyond life there are'—his face grew ashen with terror—'things that I cannot distinguish. They move slowly through angles. They have no bodies, and they move slowly through outrageous angles.'"
"'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."
"'God, they are breaking through! They are breaking through! Smoke is pouring in from the corners of the wall. Their tongues—ahhh—"'
Frank Belknap Long, The Hounds Of Tindalos