Grimora

Grimora is a species of parasitic leech that causes dragons to become rabid.

Description
The Grimora lives in fresh water in order to attach itself to the body of a dragon. As it attacks, the effects of its toxin will start to take over its host quite slowly in order to go completely savage.

Weakness
The Grimora's only known weakness is salt, which drives it out from the dragon's skin the moment the salt makes physical contact with the host. While salt can clearly hurt them, it doesn't seem to kill them, as even when submerged in salt water for several seconds they flew out of the water with seemingly no damage.

Symptoms
Symptoms of Grimora infections include the dragons going feral and rabid. Dragons lose control of themselves and turn against their riders without hesitation. They become crazed and hunt them down in whatever ways possible.

Another symptom is uncontrollable drooling of glowing saliva from their mouths. The color of the saliva greatly reflects the color of the host's fire.

Trivia

 * The mouths of the Grimora are similar to those of a Whispering Death.
 * The side effects of the Grimora are similar to rabies.
 * The glowing saliva from the effected dragon is like the foaming at the mouth.
 * Another possible effect may be hydrophobia, or fear of water. At least with Stormfly, who usually loves the water, refused to get near it. This fear is another symptom of rabies.