A humanoid Federation species with pale hair, heavy brows and long moustaches, represented by a Starfleet helmsman, a Federation President and, centuries later, a cheerful archivist.
The Efrosians were created for the feature films and never named in dialogue; the term comes from the production, in honour of unit production manager Mel Efros.
The first is the helmsman of the USS Saratoga, seen as the whale probe disables his ship in The Voyage Home. The best known is the Federation President of The Undiscovered Country, played by Kurtwood Smith, who orders Kirk and McCoy not to be rescued from Klingon custody and is saved from assassination at Khitomer.
Discovery brought the species back in its fifth season. In Labyrinths the archivist Hy'Rell welcomes Burnham's crew to the Eternal Gallery and Archive.