Ash moth
Grey as the ground at Emberfall, and it leaves a smudge of soot wherever it lands.
A pet. It is kept on your profile rather than in your bag, so it cannot be sold, banked or lost, and it can be found again. Every find is told in the world's chat.
What drops it
The Emberfall Herald
1 in 3,000
Rolled on its own on every kill, rather than from the loot table, so it takes nothing away from anything else that falls off it.