This aide was played by an unknown actor. He was described in the script as a "Q aide" or "a grey-uniformed Q military Aide".
These Q, seen in the forms of three male and two female Humans, a dog, and a scarecrow appeared in Q and Quinn's manifestation of the Q Continuum, as presented to fall within the comprehension of Captain Kathryn Janeway and Tuvok.
This shadow asked Q for a report on his progress with Amanda Rogers. Q informed him that, "As anticipated, there have been some problems… but the Humans are cooperating. I need more time. There is a possibility we won't have to terminate her." (TNG: "True Q")
This Q, who was identified in the script as a "Q Shadow", was voiced by an unknown actor.
According to the script notes, his appearance was described as "Suddenly a DARK SHADOW appears on the wall ahead of him. Q stops, annoyed. We HEAR the voice of the shadow… it is futzed and sepulchral."