Source: Incident at Absalom Station, pg(s). 61
A void zombie looks like a walking rotten corpse with a broken lower jaw and a bloated light blue 'tongue' (which is actually the akata larva's fanged tail) dangling from its mouth.
After an akata kills a humanoid with void death, its strongest larva enters the host's brain, gestates, re-energises it and takes control over the corpse, turning it into a void zombie. Akata larvae requires from a week to a month to grow into an adult; when it's about to do so, the void zombie will seek out a shallow hole or crevice, vomits the larva out, then becomes inert and topples over now that the larva animating it is no longer present. The full-grown akata will quickly emerge after a few hours and takes its former host as its first meal.