Underneath a quick sketch of the individual there is a collection of notes written by Zuri:

Name:
Mimic (Internal Designation Unknown)
Role:
Mimic voices, confuse targets, possibly assimilate.
Allegiances:
Alusair's hive
Threat:
High. DO NOT TRUST VOICES OR LIGHTS IN THE WOOD.
Location:
Unknown, likely roaming the Tangled Wood.

The first two nocturne drones used to belong to Shift, though she gave mimics to Alusair when they split during our move. As Alusair was going to stay closer to the Wood than the rest of us they'd be of most use there.
I am... really wishing she hadn't...
I know what the mimic drones can do first hand: Disorient and Mislead. One has some firefly-like creatures under its control that it uses in these efforts. They're both capable of mimicking the voices of dragons. But if you don't know what to listen for you wouldn't notice there's something distinctly wrong about how they sound, either.
They don't sound quite right, something about their voices isn't right. I'm not sure if it's because they're not dragons...
... or if it's how they learned the voices that causes it...

Several notes are in scrawled collections across the pages in this book, there isn't a name for the writer anywhere...

Mimic 4783
Last known objective: Mislead and scout.
Moderate threat

0494's mimic drones will both scout and drag smaller dragons back to the hive for assimilation. 1094 and 4783 are rarely working separately, and seem to have been obtained at the same time from another hive. They work together almost flawlessly, one or both talking while 1094 uses the swarm of glowing insects it controls as a visual distraction.