Fek'lhr is a major antagonist in the Klingon Empire storyarc of Star Trek Online, he is based on a mythological figure in the Klingon culture mentioned several times in the mainstream Star Trek lore but so far Star Trek Online is the only Star Trek media where Fek'lhr is shown as an active antagonist.


Fek'lhr is the leader of the Fek'Ihri, an almost demonic race of aliens that inspired much of the Klingons current mythology, ruling over a domain of torment for dishonored warriors he was considered neither a god nor a devil by the Klingons but nevertheless served an important role in their belief system.

By the time of Star Trek Online however it came to light that Fek'Ihr was more than just a myth and that he was a very real and dangerous threat to the Klingon Empire - standing three times taller than most humanoids and resembling a bestial perversion of Klingon physiology he lorded over the Fek'Ihri Horde and was faced by brave Klingon warriors to save the Klingon Empire.

After Fek'Ihr's death an unusual resonance signature is found after a scan of his body is performed. Theses readings match signatures recorded at archaeological sites containing Hur'q technology and implies that Fek'lhr may of been a creation of the Hur'q.