Armus Armus was a malevolent entity created by an unknown race . Armus was born as a by - product of a procedure in which a race of " titans " brought out from within themselves all evil and negative attributes that had bound them to destructiveness . The unwanted substance spread and coalesced into a dank and vile second skin . The race rejected this " skin of evil " and abandoned it on the barren planet Vagra II in the Zed Lapis sector . Armus manifested as a black viscous liquid that could also assume a vaguely humanoid shape . Tricorder scan s could not register the substance Armus was composed of . Armus was also capable of enveloping humanoids and incorporating them into the liquid , where they would remain conscious while in liquid form . Armus was capable of then inflicting suffering upon its victims while they were in this state . Armus was impervious to phaser fire , and Data theorized that it could , in fact , feed off of phaser energy . Captain Picard assumed that Armus was immortal . After the initial abandonment , Armus was left in a state of undirected rage . However , when the rage was focused , Armus was capable of generating , around itself , an intense undefined force field . With this energy field , it was capable of blocking sensor scans , communications and transporter s . It was also capable of using psychokinesis and teleportation on at least humanoid - size organisms within the field . Armus was also capable of inflicting energy discharges that caused synaptic damage to humanoids , killing them . Presumably , this field was also responsible for causing the nearby shuttlecraft 13 to experience a massive systems breakdown and crash - land on the planet in 2364 . Armus waited for someone to arrive for the rescue of the two shuttlecraft passengers , in order to sadistically torture the rescuers . After killing Lieutenant Natasha Yar with an energy discharge when she tried to walk to the downed shuttle , Armus expected to feel amusement . It also expected that the crew would abandon the rescue effort . Even after they didn ' t , Armus realized torturing them would never be amusement enough . It wanted passage away from Vagra II , to find the beings that initially abandoned it there . Eventually , Picard was able to distract Armus long enough for the energy field to weaken to a point whereby it allowed beam ing the shuttle occupants and Picard off the surface . Following the beam - up , the shuttle wreckage was destroyed with a photon torpedo to prevent any possibility of Armus using it , and Vagra II was declared off - limits . ( ) Armus was part of Commander William T . Riker ' s memories while being infected on the surface of Surata IV and treated in sickbay . ( ) " In an alternate timeline , Lieutenant Yar was not killed by Armus , and was still the security chief on the battleship USS " Enterprise " - D in 2366 . " ( ) Background information . Concept art for Armus was designed by Andrew Probert . ( " The Art of Star Trek " , p . 102 ) The costume creation was divided between Michael Westmore ' s department ( to design the head piece of the suit ) and Makeup & Effects Laboratories ( to create the body ) . ( ) The head piece was made out of soft polyfoam with a latex skin over it . It was sculpted by Westmore and Gerald Quist . ( " " ) Westmore sculpted the head piece around a cast of the actor ' s head which he had taken . He also embedded goggles into the prosthetic piece , to prevent the black slime from rushing into the actor ' s eyes . ( ) There were three mouth holes on the head piece , designed in such a way that fingers could be easily inserted to clear the actor ' s mouth from the black goo . ( " " ) The goo was made from Metamucil and black printers ' ink . ( TNG Season 1 DVD special features ) According to Michael Westmore , the goo was water - soluble and the ink was water - based . ( " " ) Armus was played by Mart McChesney and voiced by Ron Gans . Because no oxygen tank was provided to McChesney , the scenes of Armus submerging and rising from the pit of black goo were timed with a stopwatch . ( " " ) However , the body portion of the costume disintegrated during filming , after reacting with the goo , each day of shooting . Several more costumes were ordered from the manufacturer after the first of two original ones fell apart . Michael Westmore has been unable to find an explanation for the disintegrations , as the goo was supposed to be inert . ( " " ) " " I don ' t know what else was in it , " " admitted Westmore , " " because it caused the glue in the costume – very strong shoe glue – to undo itself , and the costume would fall apart . " " ( ) According to the , Armus was created by the Vagrans , a species native to Vagra II .