Thasian The Thasians were a race of non - corporeal beings with extremely powerful psychokinetic abilities , native to the planet Thasus . Once believed to be only a myth , Thasians were finally encountered by the in 2266 . In 2252 , a ship crashed on Thasus , with a young boy , Charles Evans , the only survivor . The Thasians found Charlie and granted him their psychokinetic powers so that he could survive . In 2266 , Charlie was rescued from Thasus and transferred aboard the " Enterprise " from the survey vessel " Antares " for transportation to Colony 5 , where he could be reunited with his closest living relatives . The Thasians did not realize Charlie was gone until it was too late , however . Charlie ' s great psychokinetic powers , combined with his immaturity and petulance , made him a great threat to others he encountered . He took control of the " Enterprise " and even destroyed the " Antares " before the Thasians could intervene . Eventually , the Thasians did arrive , and were able to reverse all of the changes Charlie made aboard the " Enterprise " , but were unable to save the " Antares " . Taking on his form of centuries previous , before the Thasians had evolved beyond the need for physical bodies , a Thasian appeared on the " Enterprise " bridge as a translucent , floating humanoid head . He apologized to the crew of the " Enterprise " for the havoc Charlie had wrought on board , and for the destruction of the " Antares " , explaining that they had arrived to retrieve Charlie . When Captain Kirk asserted that Charlie should remain with his own kind , the Thasian countered by stating that Charlie was too much of a danger , and that he could never be taught to cease the use of his powers . Reluctantly agreeing , Captain Kirk allowed the Thasians to take Charlie back to Thasus , despite Charlie ' s protestations . ( ) Background information . The Thasian was portrayed by Abraham Sofaer . The alien character who appears at the end of " Charlie X " was originally to have been an elderly woman . In a memo that Associate Producer Robert Justman wrote Producer Gene Roddenberry ( on , while the episode had the working title " Charlie Is God " ) , Justman commented , " " Insofar as the old woman goes , I would like to get into that with you a little further , because I believe that this character should be the boy ' s father . " " As of 22 April 1966 , the woman was intended to be the mother of the boy Charlie , as evidenced by a letter from NBC Manager of Film Programming Stanley Robertson to Roddenberry . In an initial story outline of " Charlie X " , Charlie ' s mother was referred to as a " Ferndok " , with Charlie being half Ferndok and half Human . Also , at the conclusion of the story , Charlie was to make himself literally vanish , rather than any aliens taking him away . In a revised story outline of " Charlie X " , the alien Thasians were named in the plot . Concerning the member of the species who appeared at the end of the episode , Robert Justman , in a memo he wrote John D . F . Black ( on ) , wondered , " " Would it be more believable if the Thasian ' s image materialized on the large Bridge Viewing Screen instead [ of on the bridge itself ] ? " " When the first draft script of " Charlie X " was issued , however , the Thasian was still depicted as materializing on the " Enterprise " s bridge . In a memo from Robert Justman to Gene Roddenberry about that script ( the memo was dated ) , Justman considered , " " Does the Thasian have to be vaguely humanoid in form ? Why not this time can ' t we go completely far out and have nothing that resembles anything humanoid ? " " Justman , evidently saddened by the Thasian taking Charlie Evans away at the episode ' s conclusion , also questioned if it would be possible for the Thasian to " arrange things , " so that they didn ' t need to take Charlie away with them but instead stripped him of the abilities they had given him . In the final draft script of " Charlie X " , the appearance of the Thasian was noted as involving " special effects " and was further described thus ; " " Something begins to materialize on the bridge . As it comes into complete view , we see it has a form , depth and width and height , but no solidity . It seems to waver and half - change ( perhaps a flow of colors through it ) as though it cannot hold this state very long . And it speaks in their [ i . e . the Humans ' and Spock ' s ] tongue , but with a strange eerie VOICE that is in no way Human . " " Also , the Thasian ' s dialogue omitted the explanation that he was assuming his form from centuries ago . He had several ultimately unused lines of dialogue in the script . For example , he was very apologetic to Kirk for Charlie ' s behavior , taking blame for it on behalf of the Thasians in general , and mentioned that they had searched a long time to find Charlie . In addition , the alien assured the Humans , " " As soon as we were close enough , we took him in control . " " The Thasian was depicted using an ethereal rippling effect that was added by the Howard Anderson Company . The same effect was also used to represent the Balok puppet in . ( " The Star Trek Compendium " , 4th ed . , p . 33 )