Demonic Canines

I thought I was facing down a wolf. When night came, I quickly realized that I was facing something else entirely. Never have I ran away from anything so fast in my life. Then again, there was that rabbit... - Surprised Adventurer (experienced)

Overview

These canines appear to behave like others of their kind at a cursory glance. They can howl, and they can hunt in packs. They have thick fur, sharp teeth, four paws, and a tail. In short, they appear to be your typical wolf, dog, or hyena. However, in the dark they become something far more frightful. The claws on their paws grow longer, their bodies grow to twice their original size, their mouths become an abyss of slavering fangs, and their fur gives way to a thick hide resistant to steel. To top it all, their eyes become glowing orbs capable of making out anything in pitch black darkness, and their howls become that of a screaming demon. In this demonic form, the canines become far more aggressive and ravenous. Adventurers are advised to prepare accordingly if expecting contact with this kind of beast.
The most effective way to deal with a hostile demonic canine is to summon a source of light to force the demonic form back into the canine form. The most effective sources of light being that of holy magic where secondary reflections off surfaces is enough to effect a reversion back to normal form. Sources of light other than holy magic require primary (direct) contact. That is, an unbroken line of sight from the light source to the canine.

Types of Demonic Canines

Wolves

These are the most common form of demon canine. This kind of wolf is most likely encountered in mountain and arctic environs.

Hyenas

Instead of screaming in their demon form, demon hyenas will laugh demonically. Many mistake these laughs with that of balrogs or other such beings. This kind of hyena is most likely encountered in savanna environs.

Jackals

This kind of jackal is most likely encountered in desert environs, and their teeth sprout flames when in demon form.

Dogs

This kind stands the greatest chance of becoming domesticated, although many will question the decision. A village may host one and never know it if the night form of the demon canine hunts elsewhere. This kind of dog is most likely to be found near or even within settlements.

Foxes

This kind of demonic canine is the smallest on record. The demonic form does not differ substantially in size compared to the fox form, however they are far more energetic in their movements. This kind of fox is most likely to be found within forests.

Additional Information

Perception and Sensory Capabilities

These beasts have the same sensory aptitude of your average canine. However, their sensory capabilities are augmented when in demonic form. Particularly, their sense of taste is the most enhanced of their senses when transformed. Their sense of smell is the second most enhanced with hearing following up in third. Therefore, it is highly difficult to surprise these canines when they are in their demonic form. Should the demonic form have any reason to pursue an unfortunate adventurer, then the adventurer had best make a stand for escaping pursuit may be impossible.

Note(s) from the Archivists:

I wanted to have one of these as a pet. - Archivist Theta
Uh, which one specifically? - Archivist Enna
The Hyena, obviously. - Archivist Theta