A typical scylla flock is composed of a few dozen birds, but massive swarms numbering in the thousands sometimes blacken the skies of Skell. Scylla are obligate scavengers, picking the corpses clean. Like vultures, scylla wheel in the sky over battles, diving down en masse to fall upon bodies left behind. Flocks also roost near rocky shores where shipwrecks are common, hoping to feast on drowned sailors floating on the tide. Scylla will go as far as ripping up the soil to dig out shallow graves. Upon consuming a corpse, the flock attains an echo of its living memories and can speak with the voice of the consumed. Across the eaves of Cryxian ports, the birds mockingly call out to sailors with the voices of dead comrades, compelled to return to familiar taverns and ships by the memories of their last meal. These memories eventually fade, replaced once the birds feed on another corpse.
The body a scylla flock consumes holds great sway over its behaviour. Birds that feast on the body of a scholar may croak out passages from books that he had read. Those that feast on the flesh of a thief are attracted by and attempt to steal valuable objects. Flocks that consume a warrior can be dangerous, attacking the living with a coordination and strategic acumen stolen from the dead. Worst of all, scylla flocks that eat a magic user will manifest his arcane abilities.
For many centuries the scylla were limited to the Scharde Islands, trailing behind the infamous blackships of Cryx, much as gulls follow a ship to feed on its refuse. The flocks seek to feed on death and know they will find it in abundance wherever the ships of Cryx sail.