Yeah but THESE Hellhounds....

d12

1. Actually from the biblical Hell, on mission to Campaign World in Satan's service, seeks expert murderhobos for important jobs in ancient Judea
2. Carries cask of Hell's Libation on collar, St. Bernard-like, able to restore damaged demonic entities to full fighting strength if imbibed, mortals who sample the brew must make a saving throw or burst into flames, those able to stop, drop, and roll in time rendered permanently insane
3. Perpetually smoldering hide, even if cured, but provides superior protection from elements natural and eldritch, stinks a good deal though
4. Lap dog of Hell: very cuddly, affectionate, if current master killed uses preternatural cuteness to establish bond w/nearest available new master, asbestos safety gear required for human handling
5. Retriever: seeks and fetches specific magic items required by dark master, specializes in live capture of sought individuals, noted for minimally damaging soft bite
6. Giant hell-dachshund: bred to rid caves of owlbears, other dungeon megafauna
7. Trans-planar sled team: haul terrible outer entities about from sphere to sphere tirelessly, remain motionless awaiting commands, may only be released from harness by powerful magic, will obey any being to board their sled
8. Spell-sniffing: toxic saliva nullifies memorized spells, treats magic-users as per chew-toys
9. Monster-herder: immune to many forms of monster attack, round up and distribute to chosen locales various dungeon creatures, keeps the hobgoblins out of gnoll territory, etc.
10. Worse than rabies: infected by sorcerer-created virulence that results in mad frenzy of wanton mayhem, much hideous frothing, seeping, transmissible across many species, known to have depopulated several dungeons
11. Thief-seeking: automatically detect thieves in territory, stalks, kills without mercy, piles in heap before master's door
12.  Headless: luminous sensillae in chest detects quarry across planes of existence, effortlessly breaches interdimensional veil, emits brain-scrambling ray, opens iris-like to imprison prey in body cavity