Aoskian Hound

(from Planescape: In the Cage: A Guide to Sigil - 1995):

Sigil’s indigenous watchdogs, called Aoskian hounds, are two-headed creatures with a nasty temper. Besides a double bite, these snow-white or pale tan death dogs boast a tremendous bark.... Knights of the post never tangle with Aoskian hounds if they can avoid them. Most are muzzled during the day and only allowed to roam by night. Their ghostly pale appearance and deadly quick reflexes have caused many a second-story man’s tumble into the street, and most have been thankful for the fall. After all, the Aoskian’s bark can stun a knight long enough for the watch to arrive.

Cranium rats have their own niche, roaches and the like do well, and the night-stalking, two-headed Aoskian hounds are found nowhere else. Cranium rats still bring a 3-gp bounty from the Office of Vermin Control. Aoskian hounds cost from 20 gp (weaned) to 150 gp (grown and trained). They were first bred by the followers of the god Aoskar. The power’s been destroyed and nearly forgotten, but the hounds are thriving.

AOSKIAN HOUND: AC 7; MV 15; HD 22; THACO 19; #AT 2; Dmg ld10/ld10; SA bark; 52 M (5’ long); ML steady (12); Int semi (4); AL N (E); XP 120. 

Notes: SA - The warning bark of an Aoskian hound is loud enough to stun opponents for 1-6 rounds unless they make a successful saving throw versus paralysis; when delivering its warning bark, the hound cannot attack with its bite. The blood of Aoskian hounds is used in creating Mordenkainen's faithful hound and hold portal scrolls and other magics relating to doorways.

(from Planescape: The Factol's Manifesto - 1995):

The Prison:

The Prison’s located in The Lady’s Ward, the richest and most powerful in all of Sigil. It’s a forbidding (and foreboding) structure fully seven stories high. Unlike a lot of Sigil’s architecture, there’s nothing very graceful or soaring about its roofline. Systematically placed guard towers are the only enlivening feature of the roof. The effect’s somewhat dampened by searchlights that sweep the area constantly, day and night. (The searchlights consist of translucent gems on which continual light spells have been cast, with the resultant glow magnified through treated glass. - Ed.) Armed Mercykillen patrol the roofs walkways at all hours; they lead packs of Aoskian hounds that bay the moment they scent a prisoner outside his cell.

(Homebrew writing on mimir.net by Jon Winter-Holt):

THE HOUND:

Planar Aoskian hound [he/him] / N[E]

If you’re as curious as me about Dead Powers, then here’s another cutter I reckon you’d be interested in. It’s going to have to be the last one though, cutter, ’cause I’ve got a job to attend to y’know. Can’t stand around here rattling me bone box to you all day, even if there isn’t any point in the multiverse. Philosophy (or lack thereof) doesn’t wash the dishes, does it? Bear with me, okay, it’s been a long day.

Where was I? Oh yeah, the Hound. As the name suggests, it’s a dog. An Aoskian hound, to be precise. They’re the two-headed vicious sods that the Red Death are so bloody fond of. Well, we’ve got one of them in here too.

Of course, it’s more complicated than a mad dog. (The Athar’ll pike themselves when they hear this!) See, I reckon that the Hound might be (and I’ll emphasise “might”) a vessel containing the barmy spirit of Aoskar himself.

Stop that laughing at once, berk, or I’ll be on me way now! I hear enough cackling on the ‘Wing as it is. Of course there’s reasons why I think that. I might be going barmy, but I ain’t gone stupid yet.

Okay, try this for size. Aoskian hounds ain’t normally very smart, and they certainly don’t talk. I’ll swear this one says the word “Aoskar” when it barks, though. Of course, there’s more: the dog can open portals by howling. Not just any old portals mind; these are proper ones to and from the Cage. They don’t need keys to work ’em, neither. ‘Till we discovered that, the sodding dog kept on escaping. We set up magical planar wards to stop the portals, but the damn hound could still open ’em up! We eventually found that an anti-magic shell’d do the trick, but not before we lost the dog another time.

What’s more, from its cell on the top floor of the ‘Wing the hound just stares out of the barred window. I’ll swear it’s looking across the Ditch to the Shattered Temple, and I’ll go further in saying that it whimpers at it stares. Believe me now?

Perhaps if I told you the dog gets visitors, then you’d consider it? Yeah, visitors. In fact, it’s that barmy dabus, Fell (if there’s anyone who should be in the ‘Wing it’s him). ‘Course, it’s against policy to let a visitor see one of the inmates, so Fell leaves messages with us. No, he don’t write ’em, he hands ’em over in bottles. When you uncork the top, the rebus-pictures come billowing out (you’ve got to be careful not to shake the bottle around though, or they make even less sense than usual).

Well, we couldn’t make head or tail of the messages. No, we didn’t give them to the dog; that’d be ridiculous! How could a dog open a bottle (even if it was Aoskar)?

Why a hound, you ask? Good question, berk. Listen, much as I hate to admit it, there’s something in the Godsmen’s philosophy that strikes a chord with me. They go on about reincarnation and such, and it gets me thinking. When a power dies, does it get reincarnated? Maybe it does. Now, if that power didn’t do very well, it might come back as something less powerful like, say, an Aoskian hound? How futile’d that be? You get to the level of a power, only to come back as a lousy dog! Think about it…

For the moment, we’re keeping a very tight grip on the dog’s collar. I happen to know that some splinter group of Signers calling themselves the Will of the One are very interested in getting their hands on the Hound. Shame that, ’cause they’re certainly not getting him; not while I still draw breath, at least. Signers? Make me sick, they do.

Bitter, me? Never! There ain’t no point.

Source: Jon Winter-Holt