Overlooker The Overlookers were an alien race from the Delta Quadrant . The overarching polity or sociopolitical entity to which the species belonged and comprised was called the Hierarchy . Their species was highly adept in the skills of espionage and remote surveillance . Physically , the species was humanoid with dull brown leathery skin and generally nondescript features . Their heads were lumpy and hairless , with few distinguishable facial features , having no eyebrows , lips , or nose – though nostrils were present . Their ears were similarly understated , marked only by subtle embossing around curved openings on the sides of their heads . There also appeared to be two vertical rows of at least eight raised pits running down the back of their heads . Additionally , members of the species possessed a rotund appearance with a relatively nonathletic build compared to other humanoid species . They regularly used surveillance on passing ships to plan future raids . This was done by special surveillance ships , hiding in nebula e for example , which used highly advanced ( compared to other species ) sensors to assess the tactical risk of attacking passing vessels and the value of their cargo . The Hierarchy ' s cloak ed ships also allowed them to sneak up on targeted vessels , after which they would execute a predetermined attack pattern , such as the type 3 or type 4 stealth assault . Their attack patterns were numbered according to their increasing levels of energy expenditure . The Hierarchy was meticulous when it came to the use of energy and resources on its vessels . Every planned use was to be reported and consulted with the Hierarchy to maximize efficiency . ( ) The Hierarchy itself was regularly consulted by crews of its ships using a special communication system . The situation was detailed on a sort of PADD , then entered in a slot next to a cylindrical horizontal display . Changing colored patterns would subsequently appear on the display to indicate the Hierarchy ' s decision . The social and working ethics of the Hierarchy differed dramatically from those of Starfleet in that every crewmember had only a single duty and workstation , minimal social interaction , and limited access to the rest of the ship . However , some members of the Hierarchy were known to leave their territory and explore other areas of space ( ) , and the Hierarchy , while omnipotent , was not necessarily appreciated by all Overlookers : Phlox , in particular , befriended the Doctor after getting to know him ; he came to admire how he had evolved past his original condition – something that was beyond reach for a member of the Hierarchy ( ) – and went as far as warning the Voyager crew of the impending Hierarchy attack to prevent their destruction . Similarly , Nar came to sympathize with Captain Janeway during her detention , and willingly knocked down his superior to allow her to escape ( ) . A Hierarchy survey vessel was one of the many that got trapped within the subspace anomaly known as . The Hierarchy crew joined Captain Janeway ' s alliance , where they uncovered an imminent threat with their espionage techniques . ( ) Overlookers also seem to have a taste for mud baths , as suggested by Zet . ( ) Appendices . Background information . The species was not named on screen but the reference book " " ( p . 329 ) described them thus ; " " These are high tech ' spies ' , but nobody here is James Bond . . . they ' re more like office workers . . . cogs in a vast , alien bureaucracy that we will come to know as the ' Hierarchy ' . In later episodes ' The Void ' and ' Renaissance Man ' , the shooting scripts refer to them as ' Overlookers ' and ' Overlooker aliens ' respectively . " " Specifically , the script for " The Void " describe them as " the hefty , nervous species known as " the Overlookers . " The call sheets for the episode " Renaissance Man " , dated Thursday and Friday , mentioned the interior of the " Overlooker Ship " ( built on Paramount Stage 16 ) and listed Zet and Nar as " Overlookers " in parentheses . The costume worn by Andy Milder and Mike Satterfield features a costume tag which reads " Andy Milder , # 270 Renaissance Man , Overlooker Nar " and " 224 Tinker , Tenor , Doctor , Spy , ND , Mike Satterfield , Overlooker " . Apocrypha . The Overlookers appear in the " Delta Rising " expansion of the online game " Star Trek Online " " , " though they are simply called the " Hierarchy " , even as a species . The Hierarchy are portrayed as highly adept in intelligence - gathering , surveillance , and combat support , and can join the player as allies during a conflict with the Vaadwaur . One of the storyarc ' s mission also allows the player to obtain an Overlooker Science Bridge Officer ( in - game referred to as a Hierarchy Science Officer ) .