Adventure Backdrop: Deep Roads

I've been playing a lot of the computer game Dragon Age: Origins recently and I've really enjoyed the great writing of the game: they really put together a deep and interesting history for the game's setting.  One of the elements of this history keeps inspiring me with adventure ideas and encounters every time I think about it: The Deep Roads.

In the game's history the dwarven people once had a vast underground empire.  The cities of this empire were connected by a massive series of tunnels that the dwarves had dug and that spanned hundreds of miles underground.

This idea, a series of underground highways, just keeps inspiring me as a DM.  What heroic adventures must have been undertaken as those roads were first carved?  What difficulties must have faced those undertaking the creation of such an ambitious work?  What troubles and opportunities did the Deep Roads create during the heyday of the dwarven empire?  And after the empire's fall, when the deep roads were lost to them, taken over by horrors from below, what opportunities for adventure do they present?  Who could resist the lure of the lost treasures of a dwarven empire?  What needful items might be lost down their dark and crumbling avenues?

In the coming days I will be posting some encounters, creatures, and adventure seeds that take place against this inspiring backdrop.  For today, I refer you to one of the creatures that slithers along the dark passages of the underdark: the Crawling Drake.

Crawling Drake

This creature's common name is something of a misnomer, as this dragon-like creature has no legs, just a scaly, sinuous, serpentine body and a pair of muscular wings. Able to rise and strike by propping itself up with its wings, these drakes deliver vicious wounds with their snapping jaws.

The origin of their species is speculated to be a mixture of dark things of the underlands, such as a corruption of fang dragon touched by creatures from the outer realms of cruelty and madness. Able to speak a few words of broken draconic and undercommon, crawling drakes are not especially intelligent, but they are tremendously fearsome, nasty and cruel.

Crawling drakes are crafty combatants and adept stalkers, and so will ambush their prey when possible. Once they pick a target, they will attempt to crush them in their coils while delivering bite after bite.  If possible they will attack the weakest-looking member of a group first.

Presented below is the wyrmling version of this monstrosity, as it is encountered while still young and relatively small.

Wyrmling Crawling Drake Level 5 Elite Lurker
Medium Aberrant Magical Beast (Reptile)- XP 400

Initiative +11 Senses Perception +9
HP 96; Bloodied 48
AC 19 Fortitude 17, Reflex 18, Will 16
Vulnerable 5 poison
Saving Throws +2
Speed 4, fly 8
Action Points 1

Powers

Venomus Bite - At-Will, Standard Action, Poison
+10 vs AC, 1d10 + 4 damage, the target is grabbed, and make a secondary attack:
Secondary Attack - Venom
+8 vs Fortitude, 1d6 + 4 posion damage and ongoing 5 poison damage (Save Ends).

Crushing Coils - At-Will, Minor Action
Target must be grabbed
+8 vs Fortitude, 3d8 + 4 damage and the target is weakened until the end of its next turn.

Hypnotic Coils - Immediate Interrupt when Attacked, One target within close blast 5, Recharge 4-6
As you prepare to strike the loathsome beast, its moving coils cause a sudden disorienting vertigo.
+6 vs Will, the target is dazed (save ends) and takes -4 on the triggering attack's to-hit roll.

Alignment Evil - Languages some Undercommon, Draconic
Skills Perception +9, Stealth +12
Str 18 (+6) Dex 21 (+7) Wis 15 (+4)
Con 12 (+3) Int 9 (+1) Cha 9 (+1)

A character knows the following about crawling drakes with the following Dungeoneering skill checks:
DC 15: These large aberrant reptiles, called Crawling Drakes by the dwarves, are dangerous hunters of the caverns below the surface.
DC 20: Crawling Drakes use a venomous bite and their crushing coils to kill their prey, and have strangely hypnotic power over men's minds.
DC 25: Ironically, though venomous, Crawling Drakes are themselves particularly susceptible to poison.